I have tried my hand at blending a few times. What I like to do is to try the new blend immediately - then revisit it as it ages and mellows together (1 wk, 2 wks, 1 month, 3 mnths, etc...). I'd also say that a week is too short a time to get full idea of how they'll marry.
Just a couple blending tips, use portions that will convert into 16 (as 16 is 1 pound), and if you like it, you may want to repeat it. Write the recipe down. To blend, put constituent tobaccos in a large bowl and get your hands in to toss the mixture well - kind of like a salad.
If you want the tobaccos to marry more quickly, when you get it mixed, put it into something which you can compress. I like to put it in a zip-lock and I have devised a way I can press it with a couple C-clamps. This get the tobaccos as close together as possible, helping them to marry. I have done a couple blends where I press some and leave a portion in a zip-lock without pressing. It is amazing the difference after 1 wk, 1 mnth, etc...
Have fun with it!
If you go to this website
http://www.cornellanddiehl.com/tinned_blends.htm
in the tinned blends, look for Back Porch - it is my recipe for a blend. They also used to have a blend called Orthodoxy, but they can no longer get any Syrian Latakia (one of the constituent tobaccos), so they cannot make it.