Where is my Clothier?
In order for the Clothier to spawn, ALL of the following must be met:
- Skeletron must be defeated
- All NPCs that have spawn requirements met must have a home
- A vacant home must be available
Once all three are met, give it a few in-game days and he'll arrive. The number one thing I would recommend checking is that your houses are built correctly. It would also be a good idea to create a couple extra homes in case one of them isn't built correctly or if there are multiple NPCs waiting to spawn.
You need to have a house built with all the correct specifications for the npc to spawn and live there.
A simple plan is to build an "apartment" building. In order for everyone to have a spot you will want at least 11 "apartments". This is for housing for all available NPC's and an extra one for you. The only annoying part of the apartment complex is that goblin/snowmen spawns may kill one or several of the NPC's so that they would have to regenerate.