Didn't discover the "maneuver node" feature until the return from a Dres + Jool mission a few months ago. Yes, I have been playing this game for several years by literally winging it and doing micro corrections.
Same story for quick-saves.
As a result, I rarely bothered constructing ships in orbit, so I created these silly big rockets to boost everything into orbit in a single go, computer did not approve.
Never landed on Eve, that place is scary!
To save time and money I use one solid rocket booster and a separatron spam in order to catapult kerbals to a duna transfer, lets hope HSE never visits!
I start to design ships purely for a mission, but then decide to "expand" on capability, usually ending up with Frankenstein's impractical space monster machine.
One more than one occasion I have arrived at a new planet, and discovered that I only brought a single kerbal for the entire mission, having to leave the mothership unmanned while the kerbal takes the lander down.
I take kerbal shaming images!