Most important tips

I would like in this website a list of the most important things that a noob or an average player should know. I do feel bad for people that makes these old mistakes that we all regret from the past(if you agree with me)
1)Dump high level eeves. Any level 27+ evee can be usefull regardless of IV.
2)Blue incubators for 2 or 5km(kind of personal, for me only 10k are worth) if you can't put real $ in the Game
3)Buddy System for Pokedex. You know that there is only 3 or maybe 4 mons worthy to be a buddy.(if you are not looking for a Espeon).
4)Dump high level low IV. Save some high level low IV mons to attack or prestige and dump them to save potions. Mass evolutions of Magneton, Clefables, Kinglers, and even Azumarils and Raticates over lvl 27+ serves to this purpose.
5)Spend Stardust with trash. Only for the Big 7 and their most efficient counters with the right movesets like Eggs and Champs with high IV

I wish to know if you disagree with anything i said and if i forgot something. what are your regrets.