I have started my first pair of Opal socks and have successfully completed one and have started the second sock only to discover that the patterns do not match up. I would like them to be identical, any ideas?
Start from the other end of the skein?
No, that won’t work - then your striping effect will be opposite (ask me how I know!!) 
You need to start both socks at the same point in the color strip. If a 2 ft long red section leads into a 3 ft long blue section, then there’s a 4 ft long red section - start both socks at the same point in the same color sequence. I’ve never used Circus so I’m making these colors up, but you get the idea.
Personally, I don’t worry about it. I rather like any of mine that are a little bit off, just as much as the pair that goes oposite. Don’t think I’ve ever worried about it so don’t have any that match even close to perfectly. But that’s just me!
Thanks for the info. I actually tried starting the second sock with the colours started in the first sock but guess I’m not a very good judge of measurements - totally off but feel better that it DOESN’T have to match and I think my son will like them (or probably won’t even notice)
Because Opal is in 100gr balls it is more difficult to match perfectly. I measure and write down the length and colour and sequence etc before I start knitting the 1st sock so it is easy to match up for the second.
When using 2 50gr balls like Regia it is best to find the matching sequence and cut off to match before you start the first sock so you know that you are staring on an identical place.
However, Regia sometimes has the quirk of having one ball wound ‘backwards’ so if you cannot find a matching sequence no matter what you do, try rewinding one ball and start to look for a match up from the other end. It will be there somewhere! I just had to do that for Regia Schatten Night.