I had the same question a couple years ago and I could not find any books that tailor to what I was looking for.

@Jason Rogers Well, for all of it's limitations, the 50% rule is tailor made to answer a question like this! 

I have a long list of athletes and celebrities as my client base so I have my business tailored to support their schedules and availability. 

I can have it tailored it for my State(s); I just need to see the basic language.  

@Heather ThompsonWhen you are in real estate, you need specialized, tailored advice.

What is posted on a listing is usually tailored to make the property as attractive as possible.

Might call him Entitled Ed, as he's entitled to other people's time after they already addressed his concerns, he's just special.His brother is Lazy Larry, not only does he not put forth any effort to search for answers, he wants to be spoon fed information that is tailored to his opinions, often based on poor practices and information.Ed's cousin is Fluffing Fred, this guy has the same family traits but is puts out bad information puffing up his strategy, probably beyond what he has actually accomplished and has unethical and illegal aspects.

I'd highly recommend tailoring the amount of mail you send to the amount of call volume you can handle.  

Remember you can always build upon that as you go through to the next property or tailor it down. 

Do you know of any resources like BiggerPockets but more tailored for Germany?