The Gear You Save May be Your Own
Anglers who don't overhaul gear each off season spend a lot more money than the frugal types who spend a few happy hours working on tackle. I must confess that I do this during the professional football season - I'm told we now have a minute of commercials for every minute of action! So there's plenty of time!!
I start by snow-shoveling off my workbench and dumping one tackle box or creel at a time on the suddenly clean surface. Then I wash, rinse and dry boxes so everything else can be put back. I should note that I do have check lists of lures, flies, hooks, sinkers et al which I use to note any needed replacements.
Repairs don't seem to take much gear. Some oil, a cleaner such as WD-40, various small tools, steel wool, super glue, etc. do the job.
Nicks in guides are no longer a big problem but you should check by running a small piece of pantyhose through the guides. If it catches, you've a crack or nick and may have to replace the guide or, in particular, the tip top. You'll need some cement for the latter. Inspect reel seats and consider cleaning cork grips and give the rod a nice rubdown to remove dirt. Look at the wrappings. You may need to add some protective coating.
Note: I use cloth rod sacks and run these through the washer and dryer yearly.
Reels require more attention. A good cleaning and some lube according to the manufacturer's directions make sense. You did retain those directions, right? Tip: I tape all of mine inside the top of tackle boxes.
Grind the reel a bit. If it's loose you may have worn gears or whatever. You have, of course, released your drags when the reels aren't in use so washers don't deform and cause drags to hang up.
If you find major problems check for local repair spots.
Lines also wear and lose length as you cut knots and such. Make sure your reel spool's properly filled. Run the last couple of feet of line through your lip. If it feels rough you need to cut some off. Note: you can also switch lines end for end, but it's my experience you need to replace lines every year or two. I use bulk spools
Sharpen hooks - a point's file from the auto supply store works as well as more expensive angler's files. Check for rust and add a little lubrication. Check split rings and remove old plastic baits, dead bait, etc. from hooks. Sort lures by type and check your collection against your needs listing. After all the only thing worse than not having the right lure is only having one, and losing that!
Flies You may need to rinse flies, check the hooks and look at heads. A shot of head cement helps. Steam squashed hackles and convert trashed dries into nymphs if you like.
I use Goop to reinforce the inside and outside seams and store waders in a cool dry place for the season. Check wading shoes to see felt soles haven't loosened - a new pair of laces is good insurance. Pairing up wading socks makes sense too. Do check wader suspenders. They seem to loosen each season.
Boats et al
This is outside the fishing area, but it's worth mentioning that it's lots easier to get boat and motor work done at the end of the season. Wait until winter and you might even get a discount.
People who put dead fish into their clothing AKA fishing vest deserve to smell like the local fishmongers. I check everything, reinforce buttons, test waterproofing etc.
Follow these few simple steps and you eliminate a lot of problems next year.