Dancing - in your room, at a club, wherever and whenever, dedicate your dancing to him - if you consider yourself a maenad, you could try to learn the dances of the ancient maenads (images: 1 2)

Music - listen to music that reminds you of him, make a tape or cd compilation of songs for him

Wine - obvious, I know, but drinking wine is important - and saying a prayer over every glass of wine (or any intoxicant, for that matter) is a good idea too - and if you're interested, you might try making your own wine too.

Libations - basic Greek practice, wine libations being of course particularly special for him

Theatre - go see a play, or even a movie, in his honor, or simply sit down and read some of the Greek plays (remember that they were all written to be performed at festivals in his honor)

Epithets - learn all of his names and titles, and meditate on what they reveal about him - he is after all the many-named god

Books - read every book you can find about him, fiction and non-fiction.

Festivals - celebrate the ancient festivals in his honor; there are also new holidays for him created by modern worshippers.

Public Devotions - such as creating an online temple or joining a group of Dionysians or hosting an open festival

Jewelry - wearing a piece of jewelry with grapes or ivy on it all the time will remind you of him and simultaneously be a public demonstration of your devotion

Tattoos - if you're absolutely certain of him, you could get a tattoo in his honor, a very permanent way to dedicate yourself to him

Plants - grow and tend ivy or even grapevines, and you can use the foliage for garlands

Ekstasis - at least once in awhile, do a ritual where you try to go as far outside of yourself as possible, and invite the god in. This is tricky and even a little risky, so not everyone is comfortable with it, but I think it is essential to Dionysian worship. This could be going out into the woods at night, and drumming and dancing in front of a fire until you collapse. It could be taking certain substances and letting them open you up to other worlds. It could be sitting still and chanting his names until you lose yourself in him. It could even be astral travel. Anything to open yourself enough that he can come and liberate you. And besides communion with the god, it will also have the effect of loosening you up in general, just another reason they call him Lusios!