The basic tools were, for students and small shops, drawing board, T-square, triangles (30-60-90 and 45-45-90 and sometimes adjustable-angle ones), pencils (non-repro blue was favorite since it didn't have to be erased, but black was used too), compass sets (center-wheel K&Es (Keuffel & Esser) and Dietzgens were probably favorite) and Rapidograph technical pens for lining around curves because the ruling pens in the compass sets didn't really want to go around curves and would blob. Erasers were important, both ruby for ink and kneaded for pencil. Most finished work was done in waterproof india ink.
Bigger shops used "drafting machines" (you can find them on ebay still) in place of the board, t-square, and triangles, but also the compass sets, pencils, Rapidographs, and erasers.
Depending on the industry, one might have a set of french curves and/or a spline / ship's curve set. Splines were more general because they could be shaped, but trickier to use because they could be re-shaped accidentally.
There were (still are, I suppose) standards for the types of crosshatching to indicate material, the angles and distances at which dimensions and legends were added, etc. The standards varied by industry.
Calculation was usually done with a slide rule.