I have a friend who got this game a month ago. He's MG1.
I'm GNM (right below him) now, too. I don't look up flashes or smokes or anything, I just know how to play the game. You just need good fundamentals if you want to get out of silver. (e.g stop running and spraying, practice your aim with rifles and things, check every spot they could hide, coordinate pushes and coordinate holding sites, listen for footsteps and nades you haven't thrown) Being comfortable with the map is probably important, I don't understand how to hold or take certain sites yet. (like Mirage and Cache and stuff)
Simply watching a beginner's guide will probably help you a lot, it's important to get good advice before bad habits set in