Tube Flavor

+2 on what @jtcf said.

Start with preamp tubes if a separate preamp is used.

Then small signal input / driver tubes in the amp.

NOS tubes if possible for these, or try PSVANE "art series" where applicable [better than 50% of my better NOS tube collection]. Allows one to hoard the NOS stuff a bit too.  

Buy tubes from a reputable seller with a guarantee, it will pay off and many times end up with better tubes.  

And, yes, some tubes and interconnects can compliment -or- detract from each other.

You kinda need to know what type of sound you are going for to get "there" or its hit-and-miss and trial-and-error til you do.

Sometimes it’s helpful to lean on the amp designer to share what works, if you trust them and they have proven experience on what sounds good and what does not. Good amp/circuit designers know enough to help guide you some.

I too have to agree with Millercarbon. How tubes interact with your specific amp/preamp, speakers and room acoustics can be in my case a expensive crap shoot without some guidance/knowledge. My first tube amp. I've been dealing with Dave Thompson for the past 2 months on Power/Preamp tube combinations that would work best with my Knighthawk and Klipsch Heresy IV's. Even sent him pictures and dimensions of my room. Dave spent another hour on the phone with me just the other night answering my uneducated questions. Very nice professor for my new Hobby. I can't comment on other tube amp manufacturers, no experience, but what I will say is that Dave Thompson, owner of Raven says you become part of the Raven family when you purchase. I feel that with Dave! His knowledge is Priceless.

Now THAT is superior customer relations!

b_limo you and rcbike should talk:-)And yes, isolation under tubed components is very effective, but I don't want to change the subject. Looking forward to reading about your experiences.

Tube rolling can be fun and it can be expensive. My experience started with necessity. I had noticeable tube rush in my aesthetix phono stage &  preamp so my immediate goal was to go ultra low noise, I consulted Brent Jessee and he gave so great starting points. I also suggest to determine what sound improvement you want- detail, airy, lush, mellow, more bass etc - and then move toward that sound. In addition to low noise, I wanted more mid and upper detail. I found the right combination using NOS Amperex BB & Tele 12ax7’s and Siemens 7308 (6922). For me, after solving the tube rush, the best all around sound was from Tele. Mullard was too soft or lush for my taste. The 7308s really enhanced detail in my preamp.