There are a few tricks to achieve this, here is one... you have a Bonsai that is desirable in all aspects accept leaf size and you're impatient to wait until it truly dwarfs itself according to its pot size.
Here is what you do... go through the tree and cut all the leaves in half. That is right... I said in half!!! Especially the very large ones. You can do this at an angle, if you so desire, so the leaf looks more natural. This will trick the plant into growing a new generation of leaves that is only the size of the portion of leaf you removed. Hence, producing a smaller crop of leaves on your new growth. This will usually work the first time, but you may need to repeat the procedure again to achieve the reduction in leaf size that you require.
It is important to remember to keep up on your daily spray misting immediately after cutting the leaves in half, this will reduce the amount of bruising you will see on the tips where you have cut. Also, remember to use a very sharp, clean pair of Bonsai shears.
Some species, such as Ficus, may ooze some sap after trimming, so put the tree somewhere that it can drip freely without worry to your furniture or other belongings. This oozing is temporary and will clot itself within a few minutes.
There will be more on this in the near future, so, keep checking in. And remember to
let us know how you make out... or if you have an interesting tip or trick you would like to share :-)