You'd have to ask one of the more experienced energy traders (Bone, Papa Roach, Rubibond007, rbobtrader,ogarb,landis82. Hey if I left anyone out I apologize, very long day)which ones to watch on a macro level. j/k and k/m crude both trade pretty well. I'm a fan of the natty spreads as well. I don't try and get to deferred on either. Bone also gave out the tip of trading spreads against each other and I think that idea has some real merit. Rbob spreads versus CL for example. Rbob and HO spreads are pretty liquid if you stick with the front couple months. Good luck.
F/H, J/V, X/Z are pretty popular. I've seen M/N/Q fly, V/X/Z fly, X/Z/F fly, and V/X vs. V/X condor. The condors I see are usually out a few years into cal 14, 15, and have seen as far out as 2020 on the H/J.