I have tried many cable clips and found most of them to be more difficult to print than they should be. The biggest issue is normally bed adhesion, which in turn is caused by skinny parts, sharp angles, aggressive fillets on every surface, and low total surface area. My normal approach to this is to make a simple model with flat bottoms, smooth curves, and even wall dimensions - especially through the corners.
Designed so that a .4 nozzle with 3 loops (perimeter walls, external perimeters, etc) will work perfectly. Works fine with PLA or PETG, it doesn't care. I print a few of when I get to the end of a spool to use the last bit of filament. Printing with mouse ears will keep the corners tied down and is recommended.
I have uploaded my small size, which is 150x15mm, perfect for 1-3M USB cables. I am happy to share additional sizes if desired.
The author marked this model as their own original creation.