Tell your boyfriend directly how proud you are of of him. Don't underestimate the power of your verbal praise and its effect on his mood. Looking him in the eye and telling him "congratulations" may seem simple, but he will genuinely appreciate your heartfelt praise and support of his spectacular achievement.

Use technology to instantly congratulate him. With ample methods of communication, you can shower your boyfriend with a variety of congratulatory messages across various media platforms. Tweet, email or text your supportive message to him. Don't limit yourself to one method -- use them all to demonstrate your enthusiasm. Be careful, however, not to rely too much on this less personal method, warns author and general internist Alex Lickerman. Instead, use this in addition to more personal congratulatory techniques.

Decorate his space with a variety of congratulatory items. Fill a room with colorful balloons and streamers and make a banner that says "congratulations." Hang it in his bedroom or living area in his home. If you prefer, place a cardboard sign in the front yard so that everyone in the neighborhood knows your boyfriend deserves a congratulatory greeting. If you choose this route, ensure the weather won't wash away your hand-written congratulatory message by using a waterproof marker or laminate your sign.

Present him with a gift to celebrate the special occasion. Buy him a small congratulatory present like a gift card to his favorite coffee shop or restaurant. If you prefer to utilize your creativity, put together a gift basket celebrating his achievement. You don't need to spend a great deal of money to make this gift memorable. Instead, focus on the reason for congratulating him and build your themed gift basket around this. If you are celebrating his graduation, for example, decorate the gift basket with his school's colors and include a sweatshirt stating his new alumni status. Fill the basket with his favorite chocolate chip cookies and finish the decorations with ribbon printed with a celebratory phrase like "congratulations" or "celebration."

Throw him a party to congratulate him and honor his achievement. Consider making it a surprise party -- assuming your boyfriend might enjoy this extra special touch. Invite his close friends and family to your place, bake his favorite cake and serve his favorite beer, for a personal touch. Invite guests to bring a gift, if they choose, to further congratulate and celebrate him.