>>10676306good quality plastic model kits like the ones from bandai or kotobukiya aren't hard at all, the only skill you need is removing nubs from where you clip parts from the runner without leaving visible marks. it will still take a while though, souen has tons of runners (pic related is everything contained in her box)
cheaper quality quality kits from no-name chinese makers may be much more difficult, as looser tolerances in the manufacturing means you might need to cut, glue, or cement parts to get things to fit together properly, or trim off excess "flash" from the injection molding process
and resin garage kits are far more difficult than both, since not only do you need to cement and fit everything together but you also need to paint them. but those are mostly just statues so not relevant to /toy/