There are mugs for any taste and sense of style. They're an extremely versatile form of gift and one of the few decorative items in the home that also have a practical everyday use.
For Kids
If the child is under five then it would be better to use a mug that's made from plastic rather than a porcelain one. If you want to avoid heavily commercial character designs, that pick ones that feature things that children like or enjoy: outer space, cowboys or animal themes. Regardless of what you choose, the design needs to be visually interesting and colourful if you expect a child to pay it any attention.
For Women
It may be tempting to go straight for the super feminine designs, however a woman is also likely to appreciate ones that are highly stylised and share colours with other crockery items they already own. Look for mugs that have a vintage style going on as they fit in with a lot of contemporary kitchen and dining ware designs. For those women who are in touch with their girly side, then designs that feature hearts or super cute animals would be the way to go.
For Men
It's easy to pick up a mug bearing the logo of a guy's favourite football team, but it's even better to pick out a mug that has a cheeky message or is just of a guy friendly design without stereotyping. Even a mug that plays on hobbies can be a handy choice. If looking for some serious style inspiration, then retro themed designs often feature images and themes that a man will appreciate.
Tip
When buying a mug for an adult, think about adding a selection of coffee or tea they've never had before. It will make the mug a bigger surprise when they unwrap it.