IThat depends on what you’re using your poster for.
If you’re printing posters for marketing purposes, such as advertising a sale or new product, then think about where they will be seen by the most people.
Perhaps place them in an outdoor A-Board, to catch the eye of people walking into your restaurant, café or bar. The poster can be clipped into place and held within a sturdy, weatherproof steel frame. Plus, you can easily update and replace them with newer posters, whenever you need.
For window displays, poster panels can provide a surface where posters can be stapled in place. While when posting smaller-sized prints on bulletin boards, you can use drawing pins. Remember, eye-level is always the optimum height for these types of poster displays.
Paste is still used to apply posters to billboards and other likely outdoor surfaces but be sure not to fall foul of fly-posting laws.
If you’re printing them to re-sell as part of your own merchandise, you might sell them in tubes and never have to worry about displaying them at all. If it’s a short run of arty prints, you might even wish to frame them.