Here are some of the projects you might try, now that you know how easy grafting really is.  

Christmas Poinsettia	With bud grafting, you can make one that blooms all the different colors
Chinese Hibiscus	Grafting lets you collect a lot of these, but saves space.  You can have one plant that has all the flowers you like.
Roses	You can create tree roses,  cascading miniatures on a trunk, or have a bush that blooms several colors.  (My favorite is a combo of all three.)
Jades	With the flat graft from the cactus section, you can create a jade tree with many colored branches (and you can keep that silly propeller jade from rotting by putting it on a green jade trunk)

   

Cactus	Grafting is the only way to propigate albinos, such as the "moon cactus" sold everywhere.  But who says they have to be on top of a little short Hylocereus?  Graft several on a nicely branched columnar cactus, and get a spectacular specimen
Totem Pole	If you're patient, you can create a spectacular totem pole of varius cactus.  Use a stock for the first graft that's BIG, and resists rot well.  I start them with Neobuxbaumia (a Baja Calif. cereus), Echinopsis (Easter-lily cactus) or Cereus peruvianus (the apple cactus).  Then add a clustering barrel cactus.  leave it for at least 6 months, then cut the top off the barrel, and add another columnar cactus.  another 4 months or so, add a clustering Mammillaria, or clustering Notocactus.  6 months later, another columnar cactus ( Philocereus azureus adds a nice colum of blue) .  Then maybe a crest.   The albino peanut used in this background is a light, but spectacular topper. (Chamaecereus)
Lift for blooms	Easter, Christmas, and the "orchid" cactus have beautiful blooms, but often potted, the blooms hang below the pot.  graft them on a tall columnar cactus, and you'll have a flowering tree !  The Zygocactus segments look like leaves, and when the tree blooms, it's a sight to behold ! ( They often grow better and faster grafted too)

 

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