strategy

Good tips all--thank you. You clearly are good players---only those who love the game/sport/whatever, become interested teachers.

Play a lot of games -- slower and/or untimed or CC games rather than blitz IMO.

Beginner level "how to from A to Z" type chess books should be helpful to you. You don't need to focus on any specific part of chess, rather you need to get basic fundamental chess ideas in every phase.

Work on developing the habit of looking at possible good moves your opponent will have!  Develop the habit of thinking as hard about your opponent's next move as you do about the move you have to make now. 

Studying common tactical patterns and mating patterns can be very helpful.