I don't use the plastic blocks, although I do have some. I prefer to use wood instead. I've been using the same blocks and same wood for almost 20 years now and I've not found anything any better.
I use treated lumber blocks, screwed together, 4 layers deep for the tongue. It keeps the tongue jack high enough, the camper will comfortably clear the hitch ball on the truck. If I need to park with the nose low, I'll use a single layer of board.
The supports under the stabilizer jacks came from a support post in an old barn. I imagine those posts were well over 100 years old when I got them. I cut them to length and will stack them sideways, depending upon how high I need them.
In the last 5 or 6 years I've been painting all my lumber so it looks a bit prettier. And with it painted bright colors, I'm not as likely to leave one behind laying in the grass.
I also have 2x4's I used for leveling the picnic table, and 2x6's and 2x8's for under the tires to raise one side to level. The highest I've ever had to level one side of the trailer was about 10 inches. I planned this well in advance and cut up several of those old boards from that old barn to different lengths so they would make a pyramid and I could easily roll the trailer tandem wheel right up them. That was some 15 years ago and been hanging on to the same lumber ever since. Those boards are all painted, and every couple years I paint them a new color. Nothing works better in my opinion. When traveling, I transport them in the side panels of the truck in my contractor's style shell over the pick-up truck bed.







