I've created a picture tutorial on basic crocheting and showing the pattern that I love to use. There are many out there and any would be wonderful! I used the basic yarn for the tutorial so you could better see the stitching, but it's just a matter of what size yarn and what size hook you use(twine would work well to). Have fun with all the colours you can use. For regular crocheting I use a 6mm hook and for the mini wash cloths on my card that you'll see below I used a 2.2mm hook. Have a look.....
Now to start with you pick your crochet hook, and prefered yarn/twine. Then you create a loop and using the hook you pull the yarn through it. Once tight, you loop the yarn through your fingers to create the tention. Then you start repeating this process of pulling the yarn through the loops, which is called chaining up until you reach the desired length. Then as below using your hook you go through one of the previously made loops and pull through the yarn. you end up with two loops so you pull another section of yarn through to create your stitching. Once at the end of each line you chain up an extra time and then find the first stitch on the way back. Now to create the ripple pattern that I love using is that you take the back loop not the front to create your stitch. If you do this consistantly then it will ripple effect.
Once you're at the end of you're desired length, you chain up again and then do a row around the other three sides to create a uniform stitch all the way around. Now with going around the outside, you just pick and choose holes close to the edge of the cloth. Then cut your yarn, pull tight and using your hook loop it through the cloth to secure it. Then, you're done!
Here is what I've created with the mini wash cloths that I've made. I'm by no means a pro and not all the edges are "straight" but I also thought it looked cute to be a bit "off". I looked around for images that would go with wash cloths and found this one and the sentiment (Kitchen Clutter set) by Clear Dollar Stamps that I thought was perfect. You can find it HERE. There are many out there so let your creativity go wild!
Hope you get some ideas from this and if you've never crocheted before, it's really quite simple and fun!