As the other answer says, if this brake system is going to be transferred to another bike, it is better left with complete length hoses and shorten them when put in the new bike.
What i suggest is to find a better way or a better spot to tie them looped. Cable ties should work fine enough, but if the hose is too stubborn or slippery, you might add a loop of duct tape around the hose in two points that once looped will get in touch. This will create friction between the hose itself and the cable tie.
AS for the spot to tie them, For the rear brake I sugest tie it in a loop as big as possible in a side of the front triangle (i.e. between and tied to at least two os the following: seat tube, topt tube, down tube). With two attachment points against the frame it is almost sure it wont move. Three points would be even better. For example, if the normal cabling route goes
For the front brake I sugest to route the hose towards the middle of the handlebar and tie it near the stem-handlebar joint. Loop it down and back to the stem-handlebar joint. Use two ties, one for the hose coming from the lever and other for the hose going out of the loop. When you look it from the front it will appear lika an "O" hanging from the stem. Add a tie at 3 O'clock (or 9 O'clock) where the hose separates from the loop. That will keep the "O" shape a little neater.
If the hose keeps slipping out, use bigger size of ties. The small ones stretch easily.
Use some protection on the frame to avoid friction damage to the finishing. There are comercially available frame protectors, but you may be able to fashion them out of old inner tube, foamy or cloth, warped around tubes and held up with the same ties.
Tie the hoses in such way that normal steering, pedaling and suspension movement (if applicable) is not interferred and it does not push against / pull from the tie points.