The most common ashtray design is a shallow cylinder with a flat base, to rest on a table. Many ashtrays have notches at the rim, to hold cigarettes and/or a cigar. In Spain, some ashtrays consist of two interlocking parts, the bottom of which is filled with water. Ashtrays are also built into cars and dustbins, and provided in toilets and other public places.
Ashtrays have been a popular advertising vehicle. Collectors look for ashtrays with clever and unusual ads, colors, shapes and sizes. Some ashtrays of the late 1940s to early 1970s were freeform vehicles for Googie styling. During the 1950s and 1960s, small personal ashtrays were part of a table setting, commonly placed on the top right-hand side, behind the wine and water glasses.