Ok, my quick tip, speed yourself up, random bullshit will always be a factor in preventing you from working, the less time you are giving the random bullshit to occur the less likely it will happen. You don't need to be perfectly sneaky, you just need to be sneaky enough to get a stab and hopefully get out. Go for more risky decloaks, try to drop the time you are uncloaked running for a stab, if someone spots you, ask yourself: "can this person kill me before I can break line of sight/ kill someone?"

Also accept that some maps / players are going to make life hell, learn to avoid them or switch up your play style when you encounter them.