You know from a previous WFMW that I love squeeze bottles for flooding cookies (filling in the outlines). But here's what I use for piping outlines and adding details...
Why are these great? No washing! You may have seen these...
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Some recommend using baggies for a piping bag. I don't. I think they are hard to control, not all that sturdy, and the tip has to be cut off just right.
Disposable decorating bags work for me.
Insert a coupler, cut off the end (most say to cut it further up the coupler, I like to cut off less of the bag, that way there's less of a chance of leakage),
...add a tip and secure with the coupler ring. Now, if you want to change tip sizes, just unscrew the ring, change the tip and re-secure.
Disposable bags are sold at bakery supply stores, craft stores and even WalMart. I buy mine in the box of 100 at Michaels. I cringed the fist time I saw the price, $19.99. I always wait for my 40% off Michaels coupon from the Sunday paper. With the coupon, the bags come to about 12¢ each. (OK...even at full price, they are only 20¢ each, but I feel better using a coupon.:)
Be sure to hop on over to We Are THAT Family for more WFMW tips! I learn something new every week. Here are a few of my previous entries: