Tools for business promotion

I'm looking for some interesting and not too expensive solutions to promote my startup, and so far I don't have any ideas. Maybe you can recommend something to me?

Online promotion? In my opinion, this is the simplest option. But, of course, you will need to invest money in creating a website, advertising and so on.

What do you think about printed products? Why not use such a simple tool to tell potential clients about the services your startup provides? In addition, there are online printing services such as printsafari, and you can find out more here. Sometimes such simple solutions as business cards or even custom calendars can be a good alternative to online promotion.