What I do is more mixing than blending -- no oven, no press, no aging. It's fun and often rewarding to create something you can't buy. So much is in proportion. So many blends have Latakia and Perique, I usually don't add those. I think cigar leaf, unflavored black Cavendish, a single leaf sturdy burley, Turkish, and single leaf Virginia give interesting accents in a mix. Probably there are other good ones. Certainly the Semois burley variant, if you like it. Often I'll get more with a pinch of this and that rather than doing equal parts. It's surprising how different a pinch of a condiment can make a mix.