Hi DW. The first tip may simply be so obvious that it doesn't need mentioning, but.....

Have (or pay) a professional to listen closely to your finished product for ANY off key note (these can be fixed so easily now it's a shame not to)

I receive at least twenty CDs a month for radio airplay, and at least two or three of them (every month) have some off key singing. That simply won't cut it in this day and age, unless you're just sending them to friends.

Second, get a mainstream CD (from a well-known artist) from your collection, and make sure that you have all the liner notes and information that IT does. Even after years in the biz, I left out some publisher's info on my last Borealis CD.....so it CAN happen

Songs and times MUST be in the notes AND on the back of the box. A Dj may be trying to get a song into a three minute space, and he/she needs to know those numbers.

Much more, but I'll let some of the others have their say.

By the way, THIS is a good idea (this thread)

Cheers

Rick