Move 1) Find cover, In halo 4 there are much more areas to move into for cover.
Move 2) Regeneration field, find cover, deploy regen field, head back out with an advantage
Move 3) Hardlight Shield, self explanatory
Move 4) Sprint away
Move 5) Etc.
It just depends on how you play, If you play aggressively, that's fine, but it's essential to find cover (At least in my opinion). Don't rush in when it's a 2v1, 3v1, etc.
Play cautiously,
It's also 5 shots now, rather than 4 as it was in reach.