(1) One way of designing a basement bar is to keep it sleek and simple, like designing any other room in the house. This way it is more of a family bar, compared to the few design ideas below (Sports, Irish, etc.).
(2) A simple design idea is to forget about the seating bar countertop and instead just have drink cabinets and an area where you can prepare the drinks. This will leave more room for a family area, pool table, couches, etc.
(3) To create a more bar like atmosphere, how about tailoring the design to a sports bar. Use a wooden countertop, hang sporting memorabilia on the walls, hang up a TV or 3, and put in a pool table, foosball table, and a darts board if there is space. Other ways of creating a sports bar atmosphere is to fit draft taps, and hang neon bar signs.
(4) Another design style to create a bar around is an Irish pub. Here the ideal design elements are a wooden countertop, exposed brick walls or wooden clad walls. Frame the countertop with wooden arch like in this picture.
Decor ideas include good ol Irish beer signs, wooden furniture, and splashes of green using small lamps shades, an Irish flag, four leaf clover decals, Irish signs (found on Etsy and Amazon), or coasters.
Look here for a great example of an Irish pub – notice how the green on the sign is a more moldy green than a neon bright green.
(5) Jukeboxes, red cushion bar stools, booths, straw dispensers, a sundae bar, black and white floor tiles, and neon signs are ways of creating a retro basement bar.
(6) Other basement bar ideas include going for a more rustic design. Plan to have the countertop base made out of stone, overhead beams made out of wood or log, and use wrought iron light fixtures (Rustic Decor Ideas For a Basement).
(7) Use contemporary leather bar stools (like the ones pictured), a granite or marble countertop instead of wood, and contemporary light fixtures made out of chrome or brush steel to create a more luxurious and modern bar design. For other luxury basement designs and pictures have a look at our post here (Luxury Basement Interior Designs).