John,
I prefer lump over briquettes but IMO cowboy is not very good lump, it will work but there is better choices available. Most Wal-marts carry Royal Oak lump which is alot better.
With lump you just need to get it packed in the ring good, pour some in and shake it around to settle in and pack tightly to get a longer burn time, when it's not packed in tight it leaves to many air spaces and burns up quicker. I fill the ring about 3/4 full and pack in good, then pour the chimney full of lit on top, works everytime.
Kingsford work a little better because it will pack in tighter and burn longer, same thing, fill 3/4 full, pour full chimney of lit on top, assemble smoker and catch the temps on the way up and start shutting down vents about 20 degrees before your target cooking temp. I normally put my meat on the grates while it's sitting off before assembly then let it come up to temp with the meat already in place, but you can add the meat after assembly and it comes to your target temp, all the cold meat will drop temps for a while but minor vent adjustments will get your temp where you want it.
Others will have different ideas and tricks but this works for me. Have fun with it and enjoy.