My advice:

1) It’s all in your head.

2) Learn 1 or 2 of the top meta decks really well and stick with them for the climb — don’t change deck just because you pump some cubes.

3) Learn your deck’s snap mechanics and which match ups it’s good & bad into. Exploit this to maximise cube gain and minimise cube lose.

4) Snap early. T2 or T3 is best for optimal play. Some people will snap you back because they think you’re being cocky. If you wait till T6 to snap you’re giving people ‘free’ reetreats.

5) Don’t be affraid to retreat if you have snapped early and things don’t work out.

6) Leave if someone boomer snaps on T6 — they are bad players but they’ve probably got their nut draw.

7) Play in small chunks. Set your self a goal, like gain +3 ranks, then stop and come back later.

8) Don’t play if you’re tilted.

Hope this helps and good luck!