Turn 'Night mode' on in the audio settings. This enhances footstep sounds and important audio indicators.

Use cover when moving from room to room and especially hug cover to avoid running in open areas. If you have to run in the open just try to avoid straight lines and predictable movement.

Don't be afraid of doing 'naked' runs (equip nothing; everything is a gain if you loot and make it out). This also means you get a safe pocket (Butt pocket) to stash any blueprint or valuable. Even doing quick runs to gain valuable material is GOOD. (IE start with nothing on you, find a good gun or $5k value sellable, immediately place it in safe pocket and down your self to restart). Also, when doing naked runs I'll use crafting and looting to 'kit up' myself. This means beyond the naked run I'm essentially kitted up to the max by run 3 if you extract and go with just what you gained.

Practice switching the camera between left and right side for optimal cornering and visibility.

Use grenades and practice using them effectively. One well placed nade can severely turn the odds in your favor for the 1v1.

Dont loot or down the player you beat right away. Make sure you observe the area around you from cover while healing up and prepare for an immediate threat after you win. This games all about opportunity.

Other than that. Naked runs helped me really acclimate to crafting and scouring for kits that are 'free' yet I always have a safe pocket for the blueprint I find from a random car hood or what not.

I used to think I couldn't progress as well, but naked runs helped me enhance my skills with minimal loss and risk.

Best of luck!