[EC900]

One trick or method actually, to bend tubing is to insert a barrier on the inside to prevent kinking. Small copper for instance there are inside diameter sized flexible spring inserts that create shape contours. .

For the flex aluminum-paper hoses, try and find a foam “pool noodle” that will fit inside the hose as close to same diameter the better. A tight rolled towel may do the trick too.

You also can try to make a plywood board jig and lay the hose out. Screw down some strategically placed wood stop blocks to hold it as you form the next bend or shape in the directions you need. Sort of snakes around the blocks in a general shape and tweaking once ready to install.