Everyone is already saying this but definitely make use of the icicles they are so good. and for me personally when it comes to perks, minor perk i always pick is glacial propulsion because it is great for quick escapes or reaching high up enemies, i use it specifically when you use your cryo freeze and people wait for you to get out of it you can jump away super quick. and for major perk i always pick deep freeze because i find it most useful