Whether you play with a relatively inexpensive production cue or a high dollar custom there are certain things that you can do to keep your cue in tip top shape.
Always store your cue in a good cue case and keep the case in a vertical position to help ward off warpage. Keep it away from heat sources (radiators, heat ducts) AND cold sources (AC vents). Wood is an organic material and as such, the basic rule to follow is never store your cue any place where YOU would not be comfortable-- i.e. the trunk of a car in summer or winter.
As you should already know, nothing affects your stroke for the worse more than a gross, sticky, filthy shaft. A dirty ferrule will also affect your aiming and sighting if (like me) you sight down the shaft and ferrule.
Keep your hands clean! Keep away from greasy or sticky food when playing, the mess from your hands will get on the cue, the balls, and the cloth. I keep a little travel size plastic bottle of hand sanitizer and a small towel to keep my hands clean when I can't, or don't want to, take time out for a washroom break. Keeping your hands clean helps keep the cue clean.
Clean the shaft with a slightly damp Mr. Clean Magic Eraser sponge. Do not use the Magic Eraser on any finished parts of the cue unless you want to ruin the finish!
I clean the ferrule, sides of the tip, and all non-finished portions of the shaft. After you are satisfied with the results, wipe down and dry the shaft with paper towel using a vigorous burnishing motion and follow that with a good burnishing with a leather slicker. Apply a light coat of good quality wax, let dry to a haze, and then buff to a high gloss with a polishing cloth. Apply another light coat of wax if needed. (It's better to apply two or three light coats than one heavy coat.) Burnish again with a leather slicker and then apply a little liquid shoe polish to the sides of the tip with a Q-Tip and burnish the sides of the tip to a nice gloss.
Once you're done playing..
 Remove all chalk from the tip. DO NOT GRIND THE TIP INTO THE RUG AT THE POOL HALL (it's inconsiderate and ill mannered)! Use a napkin or piece of paper towel to get the chalk off the tip.
 Wipe the cue down completely with a soft cloth. (I prefer to use a microfiber cloth, but terry cloth or flannel works fine too.)
 Burnish the shaft vigorously with a slicker. Burnishing works thru the action of friction and heat, so the burnishing / polishing action must be vigorous enough to generate heat.
[3 ]Place the cue(s) in a good, clean, and protective pool case.
If you get a little ding or dent (not a gouge or cut) in the shaft, you can get it out by bringing water to a boil in a whistling tea kettle and then holding the dent/ ding against the steam coming from the tea kettle's "whistle" for a few seconds then check to see it it has popped out, repeat if needed and then dry with paper towel and burnish with a leather slicker. DO NOT DO THIS WITH A LAMINATED CUE ( Predator, OB, etc) AS THE STEAM MAY AFFECT THE ADHESIVE USED TO LAMINATE THE SHAFT COMPONENTS!
Stay away from highly abrasive grits of sandpaper! I keep a nice piece of 3M Trizact 3000 grit for those times when I feel a need to quickly remove dirt and stickiness, it does the job and doesn't remove a ton of wood in the process.
Anything beyond that should be left to a competent cue repair person, someone who has both the experience and the equipment to do the job right.
BTW, a good repair person can fix gouges / nicks by filling them in with cyanoacrylate glue applied in thin layers.