Depends if you are solo etc. If 2 or 3 boxing I like blu/rdm, and like others have said, pay the money for the 18% movement legs, as you will want them eventually anyway.
For solo I might opt for /WHM if something crazy happens (no blu magic)... I mean rdm is ok too probably for the regular NI, but nice to have the na spells. I know some people swear by /sch, but I never got comfy with it/am lazy and like to keep things simple even if it fails 1% of the time.
Basically buff up to where you feel comfy to have things hitting you at the start of each floor.
Lamps
If it is lamps, run around and try to find the lamps, solo you are def hoping for same time (within 5 mins) or code (click one lamp). The worst one is order... the biggest issue with it, esp on 4/5 order is remembering what you did and where you are and not getting turned around. Generally you want to go 12345, 23451, 34512 etc to test, except putting ones that are in the right order in the right spot. E.G. first is always 12345, if 3 is lit next time do 24351, then if 2 lights up you do 25314 etc. You get used to it...
Navigation
It doesn't always work, but esp. solo it makes sense to hug left wall or right wall all the way around. About 5-10% of the time you will encounter 1 floor in your whole run that has something in the center that you could miss. Generally I liked to note every exit in the room despite sticking to traveling generally using the "hug the walls" rule. This helps you spot solo enemies which might have you back tracking and losing time.
Specified Enemy
You are looking for one enemy... I generally try to check as I am running and just have things hit me as I am going if they aren't the "nm" (regular mob checking impossible to gauge), if you get a room with 5+ it is usually faster just to subduction 1-2 times and be done with them (just check for the message that you completed the level).
All Enemies
Group enemies where you can, but you can lose them... anything that casts or is slow just take out... you can try to use blue spells and aoes close to the walls to take out hidden enemies that you can't see, in case they are there.
Boss
Similar to Spec enemy, run to find the one mob and take it out. Be prepared to engage here as some are magic resistant at times. Nothing ambu weapon doesn't destroy.
Blu spells
Can use what you like but subduction is great, some sort of healing (magic fruit?). I don't bother with wings of promy, but you get dia III'd a lot, so that might help if you don't counter with mighty guard. Other than spamming subduction I have T. Crush, and Spectral flow for essentially puks... I hate seeing puks... the good news is they are fast movers, so you can group them pretty easily so you aren't waiting on timers. E. Flutter helps with this too. Generally everything else I set to increase my MAB to boost the chance subduction one shots all the things.
Gears
I like having the Absolute virtue ranged weapon in a /ra macro for avoid discovery. For avoid kill... you can use your judgment if it is worth the time avoiding. With multiple characters you can sometimes have one char aggro the gears and hold them.
2 and more box
I typically like blu blu cor, prior to that I did either blu geo, blu cor, or blu and brd. With two blus you can save a lot of time going in two directions at the same time; however, this will drive you insane... or at least it does to me at times lol. Always laugh when you see the two characters meet but didn't see it in your head. (Best practice would be to have one person hug left wall, other hug right wall generally, letting autorun take control while you are switching between characters.) Generally when 5 minutes left I out, cause I am a chicken and hate redoing runs... only time I tend to push things is if I am trying to help someone to 100 for their clears, as it is sometimes worth risking to try for the even 5 levels.
Good luck all!