Jeff. Here is some advice I got from a seasoned investors and I've learned so far.
1. Stay away from hyphens - too risky. Double Hyphens even worse
2. Shorter is better
3. Aged names are better, so instead of focussing on registering brand new names (hand-registered names) , focus on names that are expiring.
Watch DomainSherpa.com to learn more. The same guy who is the publisher of DomainSherpa now has an online course to teach new domain investors how to properly invest, DNAcademy. It is a paid course. You can read the review I wrote - the link is in my signature.