@456 can you bonsai a gardenia?

You certainly can! Here is mine in a training pot, prior to last years bloom. It's currently in a glazed pot patiently waiting out the winter under a grow light.
They are very tempermental as bonsai but their blooms make the effort worthwhile .

I have a huge bush that needs trimmed next summer. I waited to long this year and the blooms were already set. Gardenias are 1 of my favorites so I would like to try to root a few trimming & bonsai them. Do you have a good starting place for 100% beginner?

Gardenias root well from cuttings so it's not a bad place to start. I personally wouldn't recommend a Gardenia to a 100% beginner; however, it sounds like you have a little bit of experience with plants.

A few points to remember with Gardenias:

: Repotting is stressful for them so try not do that too often.
: They don't like wet roots so try not to over water. Keep the soil just moist.
: They like acidic soil with a PH around 6.

A good flowering bonsai that's a little more beginner friendly is the Satsuki Azalea. Their requirements are similar to a Gardenia with keeping the soil acidic and avoiding over watering. They are; however, more stress tolerant then the Gardenia.

Would an encore azalea work? Thats the only kind i can get in my area without paying over $75 and shipping. I just cant justify spending that much on nature.

That would be a good alternative. Their growth habit is not as ideal for bonsai aesthetics; however, they are beautiful shrubs. Very beginner friendly and do well in pots. I have an autumn carnation variety that is enjoyable.