This may be the easiest project ever (and pretty cute if you ask me). All you need is a clear glass plate - I got mine at Shopko for $1.20, an adorable St. Patrick's Day image - I got my images from a CD I bought through ebay, a festive shamrock doilie, a piece of lace - I got my lace from Joann's Craft Store, and some spray adhesive - I used 3M Super 77 Spray Adhesive.
First: spray the adhesive on the front of your cute little St. Patrick's Day image and stick it to the back of your plate (do not try spraying the whole plate and just sticking the materials to the plate, it looks gross).
Step 2: spray the front of your shamrock and stick it to the back of your plate.
Step 3: spray your lace and stick it to the back of the plate.
Step 4: trim the lace around the plate.