I try chain yellow to orange unless its an easy mob like dodo's where I go for reds (can dodge all their specials, dont hit too hard). Grinding ep/dc I find I
1) quickly run out of monsters unless I am in a secluded area
2) often get sub-100 sp
Grinding yellow to orange I easily get 200-400 and if I can take the reds I can get an easy 500, though this depends on both the mob and class. things like aldgoats are no good unless you can dispel enrage, monkeys and wolves deal too much damage with specials that are hard to dodge, especially wolves though they do drop a bit fast so they are good for grouping. Ladybugs are good as their special is long charge you run away from it.
Moles and Dodo's are my favorite targets as they have easily dodged specials, especially moles though I seem to get more sp from dodo's they do more damage. Having second wind (rank 6 pug) and bloodbath (rank 6 mrd) helps vastly in your survival and downtime if your a disciple of war.
Know your class, know your prey, know your limits. Sometimes I don't know what to fight next so...I go punch something and see what happens. Sometimes it drops like a rock, sometimes I run away, sometimes I die, eventually I find the right enemy and know for future reference ;) Death penalty is pretty much nonexistent so don't be afraid to experiment and try some tougher enemies just remember to have your aetheryte bound in right spot.
Grouping to fight tougher mobs, usually what would con orange+ as solo also seems a very good way to gain lots of sp if you have a good round/camp. Mole caves still work wonders, so long as there isn't other grinding there.