Styrene

come up with a plan! measure twice, cut once! start out with something simple to get accquainted with what you need to work with those items, then once you feel you have the skill you need, have a go at it! I use liquid cement to glue pieces together, and cut out my pieces after measuring and drawing out my basic parts in pencil on the styrene sheet using a good strait edge and x-acto or a scoring/engraving tool. make several light cuts and take your time.

Thin styrene can also be cleanly cut with a scissors. Think of sheet styrene as using sheets of wood laminate or plywood. You sometimes have to glue several layers together to carve out the shape you want.

And stick to simple, flat shapes with straight edges at first, until you get the hang of it. Compound curves and cylinders can be rather daunting for a first-timer - I well remember the hell I went through trying to add the needed sponsons to my USS Enterprise carrier build.

When you do find a need for curved surfaces...look at using things around the house...example: disposable plastic spoons make great fenders and cowls.