I wouldn't wire at all, but use something like (narrow) strips of leather or some other appropriate material with holes at both ends through which wire (or even twist ties) is threaded to fasten things down to the desired level. But if your trees are leggy, can you provide more sun for longer hours? Sun, meaning if necessary higher wattage fluors. possibly closer to the trees for longer hours?

Thank you for the advice, i will try the strips and wire instead. Is there a way to know when the branches have permanently taken the shape? As far as lighting goes they have been outside for a little over a month now, in full sun (as close as you can get to full sun during this miserably overcast rainy spring). Wintering has given me some troubles. I have tried several kinds of "grow lights" with extremely limited success. Usually by spring they are nearly, if not entirely leafless. Which of course means i almost never get flowers.

Photo of the one in question.

It looks so healthy and happy, and if you can not worry about flowers, or maybe wait til it's even more mature (often takes long for flowers to appear on some plants), I wouldn't worry too much, though you might want to fix the mix with more grit and less potting soil... and you DO have a hole in the bottom for drainage?

The soil that it's in is a prepackaged cactus/succulent mix, since i found a lot of differing opinion on that topic. It had just been watered before i took the photo. Yes, i drilled several holes in the bottom of this pot, than filled with a layer of gravel.

NOO - No gravel on pot bottoms - an old and wrong idea! It's not going to help 'drainage' and can even be counter productive. Water tables and perch levels etc. do not apply to pot growing the same as they do in-ground... so just add lots of grit (cactus soil's usually all peat - a big no-no in bonsai) and leave it at that.