I too am experimenting, and trying to find the balance between function (i.e. not coming loose!) and complication of tying...
The front himo on my hakama are not long enough to tie around me twice, so they cross behind, then in front, then I tie them at the back. I then attach the back, tucking the back himo under the (already tied) front himo and then tie in a reef knot at the front - then do the bow as Bryan has explained above. (thanks Bryan!)
Recently I've taken to tying the back on first (temporarily, with the bow high up on my chest) then when I tie the front himo as above it helps secure the koshi-ita to my back. I then re-tie the back himo, tucking and tying at the front as before. It feels a lot more secure and feels less likely to loosen when I take a lot of ukemi this way.
This is difficult to describe, so apologies if it makes no sense!