I use Schwalbe Amotion tires (tubeless but I use tubes in them), which are highly flat-resistant, the second most flat-resistant tire they sell, PLUS I've put in flat liners! I highly doubt I would get a single flat, but things can go bad outside one's thoughts, so I take just one tube because I don't see the need for another, and if by chance I have to use that tube bike shops are not too far away, nor are places like Walmart, and since this tube is a 700x38 size it take up too much space to carry 2; and a dozen patches, 6 glueless patches (these no longer work well due to new material used in tubes, so they are only for an emergency get me somewhere patches) and three glue tubes. I also carry 4 Park boot patches. I do not replace the glue on patches every year because they rely on glue from a tube, thus there is nothing that can happen to that kind of patch that would prevent it from working even after 20 years. I do replace the Park boot self-stick patches and the glueless patches because those are only good for a year.
I might carry a lightweight folding spare tire just to get me to a bike shop, I haven't decided yet, but I am starting to lean that way.
What you carry for spare tubes and patches is whatever you feel comfortable with, what I carry is what I feel comfortable with, you might be comfortable with 4 tubes and two dozen patches, but that's an individual call.
I found a new tire iron which I really like called the Lezyne Power XL, these levers were stronger than my Soma steel core levers which broke putting on those Amotion tires! They make a smaller size but the XL I feel gives more leverage; and a single Pedro lever. Those Amotion tires are a big pain to put on and take off, because of that pain, I also take a Kool Stop Tire Bead Jack because I almost broke my VAR trying to put those tires on so I needed something stronger.
Other tools include a Park MTB3, one Allen key because it's not on the mini, but I forget the size, maybe 8mm; cheap pair of folding pliers, which I just discovered were partially broken going through my stuff for this post, so I have to get another. I will start carrying a Lezyne Torque wrench because modern bikes require that sort of tool. Tool-wise, that's it!
As far as parts go, I carry 3 heavy-duty zip-ties that are reusable, and 3 thinner black ones that are not. About 3 feet of duct tape; Loctite Superglue, the best out there; psi gauge; 3 Fiber Fix spokes which eliminate me from carrying around a freewheel tool to replace steel spokes. Presta to Schrader converter in case my pump Presta side of the grommet fails I can reverse the grommet using the Schrader side and use the converter. a couple of water bottle cage screws, a couple of extra bolts for rack mount to frame. A couple of chain links. And that's all I carry for spare parts.
I thought about carrying a spare chain, but since I've never broken a chain, I figured some spare links would be just fine.
The pump I carry is the Zefal HPX2 frame pump. Yes, it is heavier than a mini, but since I use size 38 tires, I don't want to put in 500 strokes from a mini on the side of the road, no thank you.
After 40 years of riding and only having one spoke failure due to hitting a stick, and no other mechanical issues while out on the road, I just don't see the need for carrying either more tools or more spare parts. If I was doing off-road riding or camping, I would probably carry some other stuff.
Side note regarding torque wrenches, most of you probably already know this, but when using any torque wrench never use it to loosen with, that will damage the small spring used to measure the amount of torque being applied.
