After finding that lots of the pictures I wanted to put on tees were copyright and noncommercial license only blah blah blah... I got sick of the search. So decided I'd try and make my own... Oh... and please dont steal my images... its easy enough to make your own :)
First find a corner in your house where it's not too dim. Now cellotape two pieces of white paper on each wall close to the ground/table. Then place a piece of paper on the ground table so you're creating a white corner.
Now place your object in the corner.
Use the zoom on your camera so only white background is around your object, don't use the flash. Take some photos and keep your best one.
Now upload your photo onto your computer and go to www.picnik.com and upload your pic. On the Edit tab play with the contrast/exposure and saturation/hue of colour. Do this until the white background is gone.
Then you can click on create/featured, they have on there countries to select colours on their flags, use these to recolour your rose/object.
Use various colours and effects to get heaps of different results... Your only limit is your imagination...