The first thing that you need to do is to have the text or the graphic that you want to be printed made on a computer. You will need to have a mirror image so that you can transfer it on the object with relative ease. If you print it straight, you will have to print it in a mirror image.
Print it on Transparency
You need to get it printed on a transparency. There are generally two types, soft and hard ones, you can use either one of those. Print it with a good quality printer to make sure that the printing quality is good. Once the graphic this is printed, carefully take it out and make sure that you do not touch the printed portion.
Place it on the Object
It is important that you place the graphic or text where you want to print it on the object. You can add some pins to hold the transparency in its place.
The process is quite simple. Once the transparency is placed on the object, carefully add pressure with the wooden ruler on to the print to be transferred on to the object. Make sure that equal pressure is applied at all the points in order to get optimum results. Take your time and do not do the transfer in haste. Once you are done, let the object dry. You will have a nice rub on print.