Use 25mm thickness if your using board material, plywood > MDF> Chipboard, get some chrome legs job done. You best bet is to get a kitchen worktop thats 38mm and use that. You can get it a nice colour, and you dont have to faf about painting it.
But was wondering what i can put over it to stop the constant scraping of a mouse/keyboard legs ruining the paint?
I use a home built desk from kitchen worktop. Been here at least 8 years and its still damn sturdy.
Took about 2hrs to make and cost about £20, about 4yrs ago i redecorated room and swapped it from a dark to a light top. Cost me about a tenner and 30mins to swap over.
I Just stuck a baton on the wall then 2 legs at the front.
EDIT, just remembered the first top had no edge so had to put one of the metal edges on that looked abit crap, new one is edged and looks better.
MDF.
Finish the exposed edges with a strip of pine the same width.

Yes MDF is both cheap and very strong. I would sketch out a design first and get an idea of measurements so you can go to a timber yard and get them to cut the pieces you need to size. The reason being is MDF will take forever to cut with a normal wood saw. *I speak from experience*![]()

Not really, It's quite easy to cut 18mm mdf boards with a reasonably sharp carpenters saw. A jigsaw can be easily employed for curves. What it will do it dull you blade very easily, but saws are cheap. The difficulty is keeping a straight line, so with so careful planning you can make your cuts such that they are hidden if need be.