kick and snare are vital, you really wanna get them to punch through, normally i would use 2 kicks - 1 nice boomy one so u have a nice low end to it and something a bit more punchy and high endy, normally ur kicks should peak at 90 - 110hz with DnB, layering a hihat on ur kick can also help give it presence on the higher frequencies.
snare again normally i layer on average 2, one that gives the whole sound "body" and punch on the lower frequencies (if your sample isn't enough sometimes boosting by maybe 6db at about 180 - 200hz will help) and something more "snappy" on the higher frequencies, using white noise helps give gives more snap (although try fade it in, so it acts as the "tail" to ur snare as at the point where the snare hits u cant have too many samples all hitting together at the same time)
if u want more info about envelopes (ASDR - Attack, Sustain, Decay and Release) then google it or search this forum along with others, they are the fundamentals for every sound so defo a must read). normally you want your individual beat hits to be short n choppy as DnB is fast, and if you have samples that are too long it will sound messy and cluttered if u dont
highpass some breaks, chop em up, cut the low end with EQ, create your own shuffles with low pitched hihats (then hi pass them, the reason for pitching them low is if u dont and then high pass them they may sound too tiny and hi endy )
other simple things like playing with velocities, and getting a "feel" for beat making will all come with time, practice makes perfect!