I tend to stick to the classic smallcraft hull shapes (rolling pin) and sizes (20t,30t,40t,50t) with most of my small craft, so that they can use a standard size docking bay on different ships. For example, most launches and boats have a 4.5m tube hull, so can dock with a standard 4.5m bay, while most standard pinnaces and cutters can use their 6m wide hulls to dock with most 6m bays. Different performances can be built into a wide range of 'standard' hulls, depending on the TL and role they are designed for. Different sized and shaped hulls (wedge, box, disc, sphere, dispersed structure, with wings etc) are possible as well, but they will either have to be carried in either custom bays designed just for that smallcraft (and will be incompatible with most other starship bay), will have to be carried in a cargo bay of the right dimensions, or be not carried by a starship at all and just used for local in system (world to world) flights. I also find this is a good way to keep the players guessing - if they pick up a 'Ship's Boat' on the sensors, it could be anything from an insystem slow freighter/passenger Boat to a heavily armed gunship/troopship/Fighter.