The one thing i have noticed when playing in newer players is the tendancy to rush into attacks without thinking for consequences. As everyone knows Chess is a game that requires the ability to think ahead and putting the opponent in the position were movement of key pieces is more detrimental than beneficial. I make the same mistake that i see in newer players every game, which usually costs me a better position but in new players it is way more evident. I have seen players throw away bishops for no reason literally just wanting to take a pawn that they noticed is within attack range. so here are a few tips to help new players from fall ing into this nasty trap:
1. imagine the piece you want to move in its new position, then look around, can it be taken, is it worth being taken?
2.if you are going to mount an attack, use a combo of pieces to pressure (scare) defending pieces or as backups incase a main piece is blocked or taken.
3.Watch out for the pawn structure, taking pawns can be benificial but not if it costs you an important piece or gives the opponent a better position or control of the centre of the board.
i hope my guide to thinking before you move helps you in your future games. :D