It's always a good practice to run them lower than what's printed on the side. Running them hot will burn them out faster. I just got a new tank. The coil says "Best 65W-75W". I'm vaping it at 45W. I get plenty of flavor, and vapor at this setting.
Coils last longer when vaping liquid without sweetener. I DIY these days almost exclusively. My coils last way longer now than when I used commercial e liquid.
I try to not change flavors that often with a coil. I have several tanks dedicated to certain flavors/recipes. Switching flavors all the time can ruin the flavor experience I've found. I have a couple of tanks for trying new things. The coils get messed up quicker with those ones.
Chain vaping can ruin coils quicker. If the wicking material gets burned, it can taste shitty. Chain vaping at lower wattages can be ok. But you don't want to do it to coils that can't keep up.
If you use a tank, don't run it empty. Keep liquid in it to avoid dry burning your coil. I have ruined a bunch of coils by taking a big dry hit. It irritates the heck out of my throat and damages the coil/wicking material.
I always prime my coils the same way. I start low like 25W. I take around five to ten drags at that setting. Not consecutive, it's important to let the coil wick with liquid. Then I go up 5W to 30W, and take about five to ten drags at that setting. You get the picture. I slowly work my way up to where I get a satisfactory vape.