1. Being positive and helping your teamates by giving callouts and encourage them makes them more comfortable. For example instead of ragjng and screaming because you got an instalocker just get over it and be positive.
2. Losing first round does not mean the match is lost. Yes , it may take you a few rounds to comeback but you are gonna get it!
3. If you wanna play with Egypt/Russian in SoloQ , ask them for their discord. Asking them for their discord is very useful. Not every low elo player check chat or pings.
4. Do not go for kills in a 4v1. You are gonna ruin your economy just because you wanted that kill. Well , if you got 9000 credits or it's last round. You could try. But be careful.
5. Check every corner. I know you may say "He is not gonna be there. He is not that stupid/dumb/bad". Stupid strategies sometimes work just because of this. It takes you 2 seconds to check it.
6. Do not tilt your enemies. What's the point in ruining an enemy day by saying "ez , you are trash , uninstall , go ff". In the end you are gonna get a 3 day mute just because you are toxic and thinking it's cool to flame. 7.Do not go for weapon skins. Please. I know Prime Vandal is a nice skin. But why would you go for it if you already have a Ruin Vandal with 25 bullets in it? The Prime is gonna have 7 bullets and you are gonna get headd by enemies because you reloaded or you are going to run out of bullets. 8.Don't be scared of using your abilities. Why would you make your team lose a round just because you thought that flash/smoke/tripwire was not going to be useful? Use them as most of the abilities cost 200 (one kill)
7. Playing half armor is not gonna get you killed every round. Right , sometimes you are gonna die by a leg OP hit , but.. it does not happen often and those 600 creds are going to be very important for the next round.
8. In 1v1s or 1v2s always smoke the spike as a defender. Bomb is planted. Smokes are giving you lots of possibilities (fakes , ninja defuses , bait defuse etc.)

I"ve ran out of ideas , please share any tips in the comments and I am gonna edit the post. English is not my main language so I am sorry if I made spelling mistakes.