I don't know if it will be the same for everyone but we found that flying into Stuttgart (from New Zealand - which for us is always via Frankfurt) was more expensive than flying to London and from there directly to Stuttgart.
You may be interested in Skyscanner which is the website we've been watching to compare airfares. It aggregates the flight prices of a variety of different airlines and online vendors for the route you search and the day (or month) you want to travel. If there is something there that suits you can click-through to the relevant website and book directly.
I figure with about 11-12 weeks we can comfortably see / do / experience around 20-25 family-friendly ventures within budget and without too much stress.
The interests of our family include hands-on technical & science activities (Castor, Pollux & Gemma); classical art, fashion, history (Vega); playgrounds, animals (Gemma & Kita); vehicles - diggers / planes / trains etc (all the boys); art & architecture in general (Atlas) and anything German (me)!
Not everyone is going to be interested in everything which means we may end up going 2 different ways some days, where it can be arranged and is safe to do so.
So here are some of my loose thoughts for our time based in Tuebingen:
Punt on the Gondola (if we get there before the season closes in October) or travel part of the Neckar, Rhein or other river
Walk & explore the city streets, castle, churches, gardens, museums etc
Get a town library card and borrow the German early readers that will help us learn the language
Watch the Duck race (Tuebingen) 10 October
Explore Tuebingen's Botannical Gardens (the oldest in the world!)
Experience a Christmas Market (Tuebingen 11-13 Dec, Esslingen (Medieval too), or Reutlingen)
Discover the vehicles at the Technik Museum (Sinsheim) or Mercedes Museum (Stuttgart)
Find the animals that we've never seen at the Wilhelma Zoo (Stuttgart)
Spy the classics at the State Art Gallery (Stuttgart &/or Karlsruhe)
Go up the viewing platform at the Stuttgart Rail Terminal, or climb the Killesbergturm to see over the city
Go to a (Samuel Harfst / Johannes Falk / heavy metal) concert
Taste samples at the Chocolate festival (Tuebingen) 1 - 6 December
Take the train on a castle trip – Neuschwanstein, Linderhof or Hohenschwangau; or Hohenzollern and Sigmaringen; or Lichtenstein
Visiting the neighbouring town of Bebenhausen and tour the monastry before walking through the forest
Stand among the Roman ruins (Trier)
Have fun at Sensapolis (Sindelfingen)
See cuckoo clocks (Furtwangen?), try Black Forest Gateau and see some of the Black Forest (Schwarzwald) perhaps by walking up the Bad Wimpfelpfad spiral
Our list is by no means finalised or finished. There's still more to research but I am happy with how it is coming together. The last thing that I want is to arrive and potentially waste time finding out what there is to do, when we can jump right in and JUST DO IT!
I know the boys would love to see around a factory that make electronics and one that makes construction vehicles.
I would like try the local dishes and learn how to make the ones our family enjoys; and somehow want to measurably increase my german language ability. (If I was able to improve to a B2 level on the Common European Framework of Reference (CEFR) I'd be thrilled.)
Finding things for all the different ages and preferences in our family to enjoy together is harder than I thought, especially when I don't know what that locals know that there is to do beyond the touristy things; and our family don't fully understand what it even means to see inside a castle or be surrounded by history older than 150 years.
* As a general rule the train/transport companies and many establishments look after families in Germany offering a flexible family pass for 1-2 adults and several or all children (and sometimes even grandchildren!). Such a breath of fresh air compared to the standard "2 adults and 2 children ONLY" mentality we have here in New Zealand.
I almost can't believe we've made the decision to go and are able to follow it through!
Returning to Germany has been a dream I have held dearly for a quarter of a century. Yes, 25 years!
We've got our passports; are watching Skyscanner daily; have made a short list of what we absolutely have to get done before we go; and have been earnestly finding out about what to do, what to see, and how it might all work.
It's times like this you're grateful for checklists.
We thought we'd ease the children into the possibility of culture shock by landing in an English-speaking country first - which may as well be England as flights are economical.
Then it's off to Tuebingen (Germany) and beyond.
Using the bi-lateral visa waiver agreements that New Zealand has with specific European/Schengen countries, we can stay for up to 3 months per 180 days. I wish we could secure a Residency Permit for Germany that allowed us more time and greater flexibility there but you need to have an offer of work, a study placement or a spouse/immediate family member there to re-unite with to even have a chance. Some countries accept a prescribed amount of funds as another method of longer-term entry, but that's not the case with Germany unfortunately.
My focus is on making Tuebingen home so that is where I am currently trying to find accommodation and have been looking into family-friendly activities too.
Housing if we are fortunate to find the right place will still be 3 - 4 times what we were paying on our mortgage and about double what we might be able to rent our home out if furnished. At the upper end of the market housing in Tuebingen is around 8 times dearer. That's hugely disproportionate before we even start to look at food, transport and activities.
Anyway I thought I'd jot down a few ideas about how you might decide on a place to call home:
Do you want to go somewhere similar or different?
Are you happy about coping in a place where the language / currency / customs / weather are a change from what you are used to or not?
Do you want access to specific activities / events / resources?
Do you have special criteria based on your health, vocation or family status? ie must be easily walkable, or have stable wi-fi
Are there images you've seen or recommendations people have given you that pique your interest?
While for some there may be a 'right' or a 'wrong' answer, I would venture to suggest that any place will be a valuable experience!
Once you have a few guidelines for what you want to find you'll want to explore and eventually narrow down your options. So:
Take a cursory look at the country's national tourism website and media.
Find the regional and local tourist information bureaux websites. Scrolling back through any social media site they have will show you what activities and events happen at the time of year you want to be there. Scout out the calendar of upcoming events too.
Look at photos on Flickr or via a browser image search - this is a good way to gauge the weather.
Find the local government website where an introduction to new residents to the area might be written detailing it's services; and most often there are useful street maps to download.
Search ex-patriot forums & websites of people who live there for inside tips, opinions & raw observations. Remember though that you will need to filter everything through your own unique situation.
Think about the things that you (and your family) like to do in your own area, and find out if they are available in your prospective home too. A local inner city business marketing agency website is a help to finding specific products and services