Stuart,
I have been working on narrowing my focus watching the SPDR sector ETFs, top 5 stocks in each one, and the following futures ETFs
BAL
COW
DJP
GLD
GSP
JJA
JJC
JJG
UNG
USO
UUP
DBB
DBA
DBS
DGL
DBC
DBV
PAGG
PKOL
PSTL
Couple of issues I have found with these ETFs is the low volume, and since the vol is low I really do not want to short these ETFs. I have been thinking about getting back into futures trading (but it has been about 10 years). I do like the idea since you can focus on a few things, become somewhat of an expert and get in groove trading, and as you say, these typically trend well.
Anyway, what are you doing for shorts on futures ETFs? To be honest I have not checked if any of these ETF have PUTs but again, low volume may end up being trapped in a trade.