help with waves

I have semi wavy hair.  if I scrunch my hair with the right product I can have a head full of waves and if I want pin straight I can do that too

since Summer is just around the corner and I will be spending a month of my Summer in China, I am looking for tips to do my hair wavy with little product and not a lot of time

I air dry my hair (whether wavy or straight) and I am looking for a towel of some sort to use on my hair that (hopefully) won't leave my hair frizzy.  I just recently got layers cut in so my waves are more defined

I'm also wondering about products.  I'm using Joico cream/gel and curl spray.  some days I feel like my hair is just so overloaded with product and I end up throwing my hair in a pony.  it's gets a little tired after a while

can someone offer styling tips as well?  since I've always had straight hair (the waves just really came out to play a few years ago) I don't really know much about styling wavy hair

any help would be awesome.  thanks!