How did you get your rating from 1500 to 1800?

Here, my rating is around 1500. What worked best for you to get to 1800?

My tactics rating on Chess Tempo is around 1400. Is there a difference in my tactics rating and rating here because ratings here are higher? Or am I simply not as good at them?

Since my tactics rating is not really improving, should I try to approach tactic exercises differently?

What about other parts? What is usually the best way to get to 1800? And how long does it usually take?

Watch a lot, a lot of master videos playing bullet and blitz. Seriously, watch them all. Memorize patterns, Attacks, endings, see how they handle positions and apply to yourself. Then check game, see what you did wrong,.. study endings and here you go, 1800.