I really can't help too much, but wondering if going to ehow or googling would help you just as much as here? Some people don't want to own up to repurposing anything.

Why don't you crochet something like a granny square (or something small) and see what it looks like. If you don't like the look of it before you finish off, go ahead and finish off and wash and block it and see what it does. If it looks ok, unravel your test block, re-attach and make whatever you like.

Great idea about the granny square....sometimes I don't see the forest for the trees ~~~ lol.

Thanks.

I have heard someone say to loosely wrap yarn around ironing board. Hold steam iron over yarn but not touching.Continue turning yarn until all has been "steamed".It should help.

Great ideas.....thanks for the tips.

You failed to mention what the yarn was made of......if wool, you may certainly get rid of the 'waves and ripples"....I recently unraveled something I was making, as I didn't like it. I made a skein of it by wrapping it around a box....then soaked it in warm water to which I put some hair conditioner...then, around the agitator of the washing machine and spun out all the water I could...then, back around the box to dry.....do NOT use the washing machine in any other way than to spin out the water.... agitating yarn will absolutely ruin it.
I don't think it would be wise to knit something with it unrippled, and then expect the finished product to be the
size you want..do whatever it is you're going to do BEFORE knitting something from it.
I'd try the same process with man made fabrics, but I don't know it it'll work or not. Natural fibers are very different from man made ones...but, all you're out is a little time, so it's well worth it.
If you don't know what the yarn is made from, take a small snip and burn it.....if it doesn't smell and leaves a soft ash, it's a natural product. If it smells to high heaven and leave a little hard piece, the yarn has melted rather than burned, and it's man made.

My son did this with a sweater left over from a college dorm don't-want-this-anymore swap pile that had a nice color of yarn. He unravelled the sweater and tied strings tightly around the hanks to hand wash it and rinse it thoroughly without tangling. Then he untied the strings so that air could get into the hanks and let it air dry. It lost its kinks.

These links might help:

http://www.craftstylish.com/item/9839/how-to-recycle-yarn-from-a-thrift-store-sweater

http://www.neauveau.com/recycledyarn.html

Best way to repurpose it is to wind it into even hanks, tie these in at least four places to keep each hank secure, then wash by hand in luke-warm water, swishing GENTLY. If you have a soap called Eucalan, which is designed for yarn, use that, if not use a VERY SMALL amound of any mild liquid soap - I have even used baby shampoo in a pinch. Once the yarn has been washed, lift it out very gently, and rinse it, again, luke-warm water, 2-3 times if necessary. After that lay the hanks on a thick towel, or two, with another towel on top, and roll these firmly to squeeze out most of the water. After that the hanks can be hung to dry, outside if possible, or in the bathroom as they may still drop a little. When completely dry, wind each hank into a ball being very careful not to wind tightly - when wound, the ball of yarn should feel squishy, not hard or even firm, so the yarn won't stretch.
As you can probably tell, I've done this a lot! Enjoy and congratulations for being smart enough to recognize that you don't always have to go to a yarn store to get yarn.