The front derailleur adjustment trick, the tight tyre trick
The Front Derailleur was invented by Satan. Adjusting it is fiendishly difficult unless you have adjusters higher up along the cables.
There is however a fiendish trick.
Allowing for the fact that the limit screws are such that you can over-adjust, what you do is adjust the wire so that you over-change, i.e. you can throw the chain off on the pedal side with a change.
Then you firmly grip the wire with a good pliers, end on, about 3mm from the nut. Loosen and then tighten the nut. The wire movement is limited to 3mm. Try that. Repeat as necessary. This trick makes adjustment easy. You can then adjust the limiting screws appropriately.
The tight tyre trick.
We've all often had this difficulty.
1. Make sure ALL air is out of tube.
2. Put tyre on so that one rim of it is entirely on. Put tube in.
3. Push second rim of tyre on, keeping tube in. When you reach the difficult bit, sweep the bit that's already fully on into the centre of the rim well by running around it with your thumb. The well has a smaller diameter than the outside as the well is convex. This loosens the tyre such that you can get, if you have strong hands, almost any tyre on without levers. I do this all the time.