The possibility for different words, pictures, sayings is endless. You could add a little ribbon, too.
The bottle is just a pink tinted hand soap from Walmart. The clear one was out, so I went with the raspberry one. It is the Equate brand which is the easiest to get all the goo off from the label. Trust me I tried a couple and this one was too easy!
You can also use other soaps, hand sanditizers, and even the foaming soaps.
On the inside is just a printed peice of Transparency paper. The one key is to print it on a laser printer or copy machine instead of a home inkjet printer. I just took it to Office Max and had their copy center run off a copy of a printed sheet. The soaps were about a dollar (you can get these on sale a lot if you are looking) and the sheet of transparency (4 bottles worth) was about 75¢. So in total this gift is only about $1.25 to make if you spend full price. I will definitely be buying more soap when it is on sale.
Once you have the transparency be sure to cut the saying to size and then you just roll up the label making sure when you put it in the writing will be in the front. Stuff it in the bottle and use the soap dispenser stick to arrange it inside.
Plus, you can do this with soap or hand sanitizer and with many different size bottles. You just need to be able to take the labels off. You can see other pictures of ways I used it here along with a tutorial I did on Garanimals.
If you want the template I have provided a pdf file here.
You can see some of my other craft ideas here.