O-Wool is produced in small batches. This can give your yarn a tonal, hand-dyed effect (that I love!). Some yarns and colors will dye more solid, while others will show more variation. I highly recommend alternating skeins while knitting to achieve an overall blended effect, even if your skeins appear solid.
Never alternated skeins before? For the sake of successful knitting with *any* tonal or hand-dyed yarn, now is the time to learn! And, guess what? If you can alternate skeins, you can also knit one- or two-row stripes - it's the same technique, just with two different colored yarns instead of two that are the same.
Work your cast-on and first row with one skein, then switch to the other skein and work one round. You can alternate every round when knitting circularly. In the round you can work one round of each skein.
If you have a reliable delicate cycle on your washing machine, you are in business! Washing hand-knits in the machine is my preferred method. I find that it evens out all of my uneven stitches and gives the yarn the tiniest of soft halos. I do it for *all* of the O-Wool yarns, but, if it makes you nervous, stick with hand-washing the 100% animal fiber yarns and try the machine-wash method for Balance or Balance Bulky (the 50% cotton 50% wool blend).
When I've completed my project and woven in all of my ends, I place my project in a lingerie bag or pillowcase - something to protect it a little bit. I use cold water (ideally tap cold - some machines have that option now) and a gentle detergent. My favorite detergent is Soak Wash, but I also love using Dreft which is a baby detergent you can find in most stores. I use the delicate wash cycle on the machine, and, if you have the option, a low spin setting (if you don't, that's ok - I didn't for years). Sometimes I will let the item soak for a bit before starting the cycle - this is especially good on cone yarns, or something that needs a little extra washing. When the machine completes its cycle, carefully remove the item from the machine taking care to not stretch it out. I typically lay a towel or two down on the floor in a room with little traffic and carefully spread the item out and block it to shape. If I want it to dry faster, I'll put a fan on it on low.