To congratulate a graduate on his or her accomplishment, a simple message such as "Happy graduation! Many wishes that you see your dreams come true" works well. Another option is "Go confidently in the direction of your dreams. Congratulations on graduating."
When expressing sentiments concerning graduation, there are no right or wrong words, as long as they are heartfelt and sincere. Wishes for the next stage of the graduate's life are also appropriate to include.
A humorous way to wish a graduate congratulations is "Remember what years at college have taught you: Sleep is overrated. You don't have to read everything. You can survive on Ramen noodles and coffee, but not for long. Anything is possible with your hard work."