I have been preparing 5 or 6 PTS returns for years. Potentially, 1065 returns are the most complicated of all of the Business Entity Tax Returns.
There is no single practice return that will prepare you for all of the variables that might pop up.
A 4 to 8 hour CPE class would at least get you headed in the right direction.
While it's somewhat expensive PPC's Tax Guide for Partnerships is very thorough and complete.
Ditto, done with CPEs too, just waiting on NY’s release of classes. I try to make the last 2 months of the year as stress free as possible, like it’s a vacation