Congrats on the new adventure. When it comes to an application fee, I found that if you charged a fee, people who don't meet you minimum criteria (min income, no evictions, no felony's, what ever you decided to set up as your min. requirements) will try to apply for the apartment hoping you don't pick up on a prior eviction or some other qualifying requirement. I actually went up from 25 to $40 for my fee. It costs me $35 to run the report, and the couple bucks covers anything else.
I have had people come back with the application filled out, cash in hand, and tell me a story and ask my to accept the application. Most of the time if they have to have a face to face conversation with me when they hand in there application, it is a red flag. I prefer my tenants drop off the application in a drop box.
On a side note, I have heard of some people on here in tougher areas, make the application fee reimbursable towards the first months rent. I like the idea of keeping a fee on it. I live in a strong rental market, and have not had any issues.
