It is very normal to go backwards before moving forward. I hand registered a train-load of .asia domains, as well as no-value higher extension domains before learning that the solid and liquid investments are mainly .com and .net.
The keys to profits include snapping up brandable domains and having that buyer in mind when comtemplating "should I buy this one". It is always profitable to do your homework, research aftermarket domain sales portals etc.
I have little experience in domaining, only started seriously about 4 months ago. But my latest string of sales has been an encouragment to many fellow domainers and contacts - and myself
Ares.net $21,500 (cost me $6,900)
GoFlights.com $10,000 (cost me $900)
Amatrice.com $9,000 (cost me $3,800)
iPHOTOS.net $7,000 (cost me $60)
JumpGames.com $1,700
Tequilas.net $1,500 (cost me $59)
CardsToday.com $1,500 (cost me $59)
PM for details / tips.
So If I can land these types of sales after just 2-3 months of domaining, anyone can. The key for me was reading for hours, absorbing and learning. Knowledge is very valuable....