I'm struggling to get a launch system that will move my lander to the Mun--I think it is just too heavy.
For a mun landing and return to kerbin your lander stage should not need more than 2x 400l tanks for the 1 man capsule, it's surprising how much you can do with so little fuel in low/no gravity and a low mass.
Just started playing KSP again myself. After my first Mun landing with a failed return due to little fuel and inefficient piloting, my rescue mission lander ended up so overbuilt I could take off from the Mun, fly to minmus, incline and circularise the orbit, land and then take off and return to kerbin again with fuel to spare.
Mun/Minmus roundtrip ship:
It's not a very pretty sight when this thing wobbles itself out of the atmosphere, I can tell you.
The stage that takes the ship to orbital speed and onwards, here during a slighty inefficient use of the external disposable fuel tanks.
Landing on Minmus.
First orbit capable spaceplane:
Rescue mission of the rescue mission of the spaceplane pilots that had landed back on Kerbin after the orbit. Having lost one sides engine the return trip was quite hairy.
The first landing on Mun. Unable to return to kerbin, an eventual four rescue missions were launched with varying succsess ending with the Mun/Minmus roundtrip.
I am starting to think my "No Kerbal left behind" policy might not be sustainable in the long run...
And one more shot of AirBuccaneers: