My wife would have been killed or left with severe brain damage if she hadn't worn her bicycle helmet one time. Wear one every single time you get on your bike.

Zip ties.
Front and rear LED lights.
A small small roll of toilet paper (actually, that is in EVERY kit of mine). :-)
-Blast

Pardon my ignorance, but what is a tire boot?

Can I inquire as to everyone's views of "slime" or other flat proofing tire inserts? ( Not meant as a hijack. More like alternative to tire fix-it kit? )

When choosing bike tools:
- Generally a multitool with hexes you need. Do check what the bike needs (Generally hexes, but some have screwdriver slots, Philips or torx)
- CO2 is fast, but one canister = one try. I also broke a regulator once. A pump is much more reliable.
- Chain tool and chain-link
- Spare tubes and/or patches (both inner tube patches and an outer boot)
- Proper tire levers
- Spare bolts

Some even carry spare derailleur hangers and such to repair derailleurs, but with a chain tool you can convert a bike in to a single speed.
When carrying things on the bike:
- Always pack things in plastic or other kind of waterproof container, otherwise they will get wet and rust.
- Things will rub and will cause damage, check and replace plastic bags often

Choose the location of the bags carefully. If you want to be able to throw your bike in any direction, carry it on your back. If that isn’t the case under need the saddle is my favourite place.

This is what i got in my saddle bags:
https://youtu.be/irFCgJI0V10

And what i got in a backpack for MTB'ing.
https://youtu.be/4U5RM8UvUrk

What works even better than repairing is preventative maintenance and choosing the right equipment for the job. Puncture resistance tires are a great investment.




Tire boot = patch for outer tire
Bike sealant, my experience: very messy to put in. Might clog up the valve and cause it to leak (so might need to re valve the tube). But on the other hand I have had a sealant that worked so well, it also stopped me from pumping up my tires. Had to puncture the sealant with a needle to fix it.... I now run my tires dry.

I have had problems with tire sealants; they will clog your valve. Better are protective strips between the inner tube and the tire.

When you are mounting new tires and tubes, tire liners are a good thing, but don't forget http://www.rei.com/product/545060/velox-rim-tape. A little bit of additional protection can prevent the need to break out the tools for repairs in the middle of nowhere.

My MB is mostly used on streets. Fat slicks may not be as fast as skinny road tires, but they make great tires for use in a city with potholes and cobblestone streets with the occasional gravel bike path. I have never (knock on wood) had a flat.

Coming from the other direction, I gave up skinny tires for fat (38mm) road tires for both commuting and touring. They were much better on surfaces other than pavement.

A paper towel or two make excellent TP as well as wiping off grease.

In rough order, what I'd recommend
1. helmet ( sunglasses, sunscreen)
2. water bottle
3. minipump
4. bike multi tool. w/ 3,4,5 mm wrenches
5. sturdy lock
6. gloves - look for heavier padding
7. cell phone, map, cash

yes, yes, and yes to the bell, kickstand and helmet