I have a 'boss prep' spell, typically that would be your long term debuff opener if your class has one (curse of elements, vampiric embrace, etc) Something your apt not to have in a grind rotation.

The I have a 5man / trash and a boss sequence. Typically these are the same minus the attention to longer run spells (on trahs I don't cast vampiric touch or curse of agony since nothing lasts that long).

I always have ctrl-dps key, that resets the castsequence. This helps with combat where there is a goofy fear or movement component. This would mean that immolate will run out, chaos bolt is up, shadow word pain likely fell off, etc and I will need to reapply all those and what not.

For all my dps characters I typically have matching core spells: buffseq, prepseq, postseq, boss start, dps, dps_alt, dps_boss, burst, gtfo, chug, itson, and regen. most of these have a nocombat and a combat duality to them to make them a bit lazy.

buffseq (party buff and minor managements)
prepseq (the immediate pre-pull stuff, thorns, pw shield, fire shield, earth shield, fear ward, dampen magic, focus magic)
postseq (watershield)
boss start (the once a fight debuff sequence)
dps (trash sequence)
dps_alt (alternative spells, a button i swap with the key that normally runs, this is for fire / nature immune stuff) which can mess up sequences 'you cannot do that yet')
dps_boss (playing the long game sequence with auto trinket use and minor cooldowns, includes lifetap)
burst (instant cast dps stuff)
gtfo (shadow flame, cone of cold, thunderstorm, typhoon, shockwave)
chug (eat mana pot, mana gem, thunderstorm)
itson (heroism, wrath, minor cooldowns, trinkets, shadowfiend)
regen (no channel evocate, shadow friend)