I have fixed a lot of ropes over the years. Almost all of my close-calls in climbing have been because of fixed ropes. These are just like my opinions, man.

line of sight is great

being able to see the entire length of the rope between refix points is super helpful if you are leaving a rope up for more than one day. I have had multiple ropes get scorched by rock fall when left up. If you can see to the next refix point, it should be fairly obvious if there is a life-threatening crater in your cord. Of course, you need to get into the habit of actually looking up before you ride the lightning.

avoid edges and corners.

even modest edges / rubs will blast a rope if it is stretching a lot or you are getting slapped by the crux for an hour. refix to avoid edges and even minor wear spots. rope protectors are nice, but arguably just as faffy. some pitches are easy to refix on, in which case rope pro might be the only viable option.

use the bowline on a bight

a downside of refixing a lot is that you kill the "good vibes" of a long, dangling free snake. doubly so if you get elbow tendonitis trying to untie some heinous welded figure 8 on a bight. With the bowline on a bight it's pretty much impossible to weld it, and even if you smash your microtraxions / jugs into it, you can still untie it. i dont use any other knot for fixing at this point.

dynamic ropes are fine

rumors of the woes of dynamic lines are greatly overstated. I pretty frequently fix on an 8.5 dynamic rope, and if you tastefully refix it's totally fine.

tag it

if you are leaving a rope in situ, leave you name with it. Having a bag at the base that has your name, phone number, and when you fixed it is good policy. Beyond that, it should be good accountability to get that thing out of there when you are done with it.

get that thing out of there

index in particular seems to suffer the tragedy to the commons, but i'm sure it happens a lot of places. When fixed ropes are carte blanche, they appear everywhere. They also often stay everywhere. We are all guilty to some degree, but aspire to clean up if you can. It's probably controversial but if something isn't clearly being used, I'd feel nothing taking it down. If you haven't used your rope in a year and someone cleans it, I find anger to be fairly indefensible. Of course, it's tasteful to give people their ropes back if you know who's it is, and you probably don't want a cord that's been air-fried for the past 5 years anyways.

know your place

it's not hard to kill someone else with your fixed line, tread super ultra lightly. when you rap in from the top of the crag, you subject anyone at the base to whatever you manage to dislodge. 60, 100, or 200m's is a shit ton of slop to be dragging around, and I don't believe there is any amount of vigilance that makes it acceptable to drop in above people. It's distasteful and dangerous. I love fixing ropes, but go out at night or in the morning, go to a random ass crag that nobody goes to, etc. If you are booting up at the top of the wall to drop in above people, you should feel deeply uncomfortable. Shouting down to ask what people are climbing "so you don't get in their way" is inadequate.

tie it all off

also leave no "dead strands", i.e there should never be a strand you could conceivably put the grigri onto that actually is just the tail of a knot and doesn't lead to anywhere. Coil it up, or at a minimum tie the loose straggler back into the anchor somewhere.

there is a top of the 200m spool

normally I see people coil a 200m into 3 ~65m chunks. when you start at the top of the route to drop in, make sure you have the correct side of the rope! one direction is really easy to unfurl, and the other almost always leads to tangles.