I got to learn from a great tech doing club installs. One of the first rack cleanups we ever did was aweful. Ever cable had been cut perfectly to length and was all direct wire.
We ended up putting 4 new patch panels at the top of the racks since there was no length to move gear around or change connectors and still have things fit.
Later we went to an install he had done from scratch. Same thing. Move some gear and it wasn't looking good. Very similar to the first, that is until he pulled a couple of neatly rolled and labeled bundles from the ceiling. Made moving things very easy.
Long story short, if it's a direct line (no patchbay) leave a good working loop, I generally leave 6' to10' depending on location. I know techs that say this is excessive and I know others that say it's not enough.
Things that go from patch bay to device. Make to length when possible, use velcro in the racks and bundles according to type. Network, audio, video excetra.
If you have access to a 3d printer there are some great cable accessories cheap to print and very useful.
Cable bars are also very handy.
Pictures would definitely help.
Kurtis