Sometimes when you start to decorate a cake you realize that you have forgotton to buy icing bags. this can cause a major problem in your decorating process. however there is a simple solution that will solve your icing bag dilema.
the first thing you need to do is get your icing ready. if you are going to dye it go ahead. once your icing is ready, open a sandwich bag and place whichever icing tip you would like inside a bottom corner of the bag. if you do not have any tips the bag will work just fine. place a spoon or two of icing in the bag. then cut a small hole in the corner of the bag. this is where the icing will come out. next you will need to work the icing down towards the tip opening and twist the open end of the bag shut. now you have a icing bag.
Next you can begin icing your cake. if you do not have a tip, the bag can be used to write words or create whatever designs you choose. then when you are finished you can simply throw the bag away. if you run out of icing simply open the bag and add another spoonful.
You can also place tips on the outside of the sandwich bag if you have a coupler. you cut a hole in the bag first and attach your tip and coupler the same way you would if you were using a regular pastry bag.
it is best to use a good brand of sandwich bags. off brands tend to be weaker and can bust when used as icing bags.