I don't go far enough in the my series to carry much, bottle jack, breaker and wheel socket (behind the seat), tow rope, 8mm ring spanner and aa card. If I am going further I swap the tools out of the 110 into it, and if going away may take a few more.
The 110 (daily drive) however has the same plus, full set of metric and a/f combination spanners, metric and a/f allen keys, pliers, screw drivers, 1/2" drive metric socket set, large adjustable spanner, hammer (under drivers seat). Spare wire and connectors, alternator belt and lift pump (been caught out with both of those before) in with the battery. Basic recovery gear consisting of, tow ropes, shackles, bow saw, hatchet, entrenching tool behind the seats.
If I am doing something specific or going out off roading I then have a recovery box with more extensive kit in I will put in the back, and if going abroad I may take a more extensive tool kit with me. But in the UK, the aa will recovery me if it gets really bad.
However, if your vehicle is in good order and regularly maintained you shouldn't need any tools as it should not break down. The 110 went around Morocco without putting a spanner to it and I would get in either vehicle tomorrow and drive them anywhere I needed to go without the fear of it breaking down. However, I spend a lot of time maintaining them and keeping in such a condition. The tools I carry are a fall back and very rarely get used.
My last two breakdowns were the lift pump on the 110 just before Christmas, which I knew was on the way out and should have already replaced but was short of time. Prior to that, was about 2 years ago when I ran out of fuel in the series. This was because the fuel gauge does not work accurately so I use the mileage, but I had reset the mileage for a classic car rally route and not take this into account. Being a diesel I needed to bleed the pump before it would start again, hence the 8mm spanner. But both of these were my fault rather than a fault with the vehicles which is as it should be. Your vehicle should be in such a condition that it will not break down.
The only exception to this is if you a foolish enough to believe that petrol is superior to diesel and you have taken your series land rover out when there is even the slightest hint of moisture in the air. Then the ignition system will refuse to work properly and the only remedy for this is to fit a proper oil burning engine which it is not advisable to do with tools you have in the back at the side of the road.