Items that "add height" in the game are quite numerous, but a small number of them are used to decorate houses for this purpose, mainly because of their acceptable invisibility in the stacks. A good example is the presents that could be obtained during the 25th Anniversary Event. They all add height, but we mostly use only 3 types.
I use the following items:
1) Yellow Present, Another Yellow Present
They give the least amount of the height effect. It is about 2x smaller than with Small Blue Present. In addition, the position of these presents makes them work well in more demanding stacks.
2) Small Blue Present
Probably my most used item for giving height. It is easy to hide and gives noticeable results.
3) Obsidian/Jade Zaoan Pawn (optional other chess figures)
Slightly taller than the Small Blue Present and unfortunately also more difficult to hide. Less conspicuous are the black figures, so they are the ones I use much more often.
4) Trophy Stand
This is the oldest item used to raise other items. It is the tallest among those listed above and, unfortunately, also the most conspicuous. I use it occasionally.