Choosing subsets of a set with a specified amount of maximum overlap between them
I think this problem is still open, but the following might be useful:
Ray-Chaudhuri-Wilson Theorem:
Let $L$ be a set of $m$ integers and $F$ be an $L$-intersecting $k$-uniform family of subsets of a set of $n$ elements, where $m \le k$, then
$|F| \le {n \choose m}$
$\bullet$
$k$-uniform family is a set of subsets, each subset being of size k.
An $L$-intersecting family is such that the intersection size of any two distinct sets in the family is in $L$.
The following result of Frankl gives us a lower bound
Frankl's Result:
For every $k \ge m \ge 1$ and $n \ge 2k^{2}$ there exists a $k$-uniform family $F$ of size $> (\frac{n}{2k})^{m}$ on $n$ points such that $|A \cap B| \le m-1$ for any two distinct sets $A,B \in F$.
$\bullet$
For an algorithm for constructing such sets (based on Frankl's result) refer: https://stackoverflow.com/questions/2955318/creating-combinations-that-have-no-more-one-intersecting-element/2955527#2955527