I mostly use trim to make my concentrates, since flower is more valuable, but I still love concentrates. I don't mass produce them though, I only work a few ounces at a time.
The KEY is in the material if you have really good quality trim you can get great quality concentrates. I ONLY use the sugariest sugar trim and popcorn nugs if I have any. I won't run trim with fan leaves in it at all!
If you want to try home made concentrates there are a few good options. Rosin is fantastic if you can get the process right, and it doesn't use any solvents. However I don't know how well trim works for rosin.
Personally for home extractions I advocate for QWET/QWISO. These are both alcohol extractions which are fairly simple to get right and require very little investment or special equipment. You can safely perform these at home with little risk as long as your not a moron(open flames near alcohol or the vapors is bad incase your wondering). You can get a really nice quality extract.