With coffee, herbal teas, mate, and postum, you're going to be used to a much stronger flavor. Tea can be very subtle. If you drink it right after a cup of coffee or spicy/ strongly flavored food, you won't taste it.

It can also be made pretty weak, if you're using single serving loose leaf packets in a 12oz mug, it'll be pretty weak. Those are meant for closer to 6oz. Try adding a lot more tea. Add 4 times what you normally do, and steep it for the same amount of time you normally do (unless it's usually bitter, then do less). You can make it really strong if you just add more. I like to do that with a good Irish breakfast tea.

Also, explore flavored teas! Earl Grey, genmaicha, Lapsang Souchong, mint, and jasmine teas are some really good teas.

This jasmine tea has a great jasmine flavor, it's made with real jasmine instead of sprayed with oil or flavoring. It's also super cheap for pretty high quality tea.

Harney & Sons makes a good Lapsang Souchong. It's really smoky and tastes like a campfire, if you like strong drinks, you'll probably like it. It's very polarizing, though, some people love it and some people hate it.

Taylor's has good Earl Grey, which is flavored with bergamot. It tastes like fruit loops. Fancy.

Rishi makes good mint tea. It's very forgiving, if you like mint, it'll cover up most flaws you'll find in tea. The flavors compliment each other very well.

Genmaicha is made with puffed brown rice. It tastes a little bit like popcorn, it's a little sweet because of the rice, and it can have a strong flavor.

Try other things with tea, too. An Arnold Palmer (half black tea, half lemonade) is great in the summer. A squeeze of lemon or lime juice in any tea totally changes the flavor.