[TYPO3-dev] How to keep a extbase extension compatible between TYPO3 versions

[Marcus Bieber]

Hi everybody,

I was wandering if there is a guide/links/tips to find informations about what to do to keep a extbase extension compatible through TYPO3 Versions.

What would be the plan to be compatible for 
6.2 LTS, 7 LTS to 8 LTS 
or 
7 LTS to 8 LTS

I have a 6.2 extbase extension in some customer projects which will update in different times to different Versions. 
Don't ask.... customers. 

And I'm looking for a good strategy to keep the effort low.
I couldn't find something official. Is there?

Thanks in advance for any advice.

Regards Marcus