It's kind of a recent thing for me, I tried for a long time and couldn't quite do it. That was the story until I realised I needed to stop 'trying'. The point is to let go rather than to push it.
Thoughts are fine, they come and go, don't attempt to strangle them because you will just end up in a fight with yourself. Have the thought, but don't engage in a back and forth with it. If it helps just say something like "that's nice, dear" and take your attention back to nothing.
It seems frustrating at first because the thoughts keep coming and asking to be reacted to but the more you do this the easier it gets to dismiss them after noticing they are there.
I meditate once or twice a day now, either just after I wake up or just before bed. These are the easiest times to do it because your brain is close to sleep state.
Since I started putting the work in I've noticed that I look forward to it more and more, it's a comforting place to spend time. I also notice that the things that would have ruined my day or week at one point are now just momentary blips that I am able to let go and recover from quickly.
I understand that learning something like meditation can feel like a mountain to climb when you start but the benefits far FAR outweigh the time it takes to learn.