ok so I'm in the process of rescaping/replanting my tank.
One thing that errks me more than anything in this hobby is trying to get a rooted plant in the soil without it floating to the top as soon as you let go of it/try and move the tweezers out of it. I just figured out the perfect solution. This may seem kinda basic. So far it has worked best on bigger root systems in deeper soil. What you will need: Long tweezers, spatchula/bulldozer combo. I got mine on ebay. Ok so first you put the plant in the tweezers like so.
You take it and push it into the gravel kinda wiggling it down (I think it works best in deeper soil pushing the tweezer down until the tweezers can stand on there own.)
Then take your bulldoser and level off and tamp the hole that was left from wiggling it down.
Now this is the important part push the bulldoser against the tweezers and down on the plant.
Then lift the tweezers out (kinda tricky w. one hand).
When the tweezers are out just lift off the bulldozer and bam,
no lift from the plant it just stays there. I have a gibby pleco and he knocks lightly planted stuff around but so far in 24 hours very few plants have been uprooted. Tell me what you think see if it works for you