Well, a variety of answers is likely because "small stream" may not be enough to describe what you're looking for. How small? How tight with brush? Limestoners or freestoners?
Based on the avatar I'll assume you're talking about the tight, brush and rhodo choked little freestoners with little brook trout.
I generally use Humphrey's tight brush formula, which is in both his book "Trout Tactics" as well as several of his videos. I'm sure it is based off of the same Harvey formula mentioned by BrookieBuster. I gotta tie a new one for the weekend so I'll dig it up within a few days.
7'6" ending in 3x or 4x tippet is a pretty typical starting point for me. I sometimes adjust the leader, but more often the tippet length, to get tighter casts vs. better drifts as needed. I'll go down as far as 5' probably, or as long as 8.5'. And every so often I'll go as low as 5x for the tippet.
To alleviate the blood knot problem, feel free to adjust to fit your needs. If it's only 6" lengths, then your formula is stepping down really gradually. For instance, if the formula calls for (not a real formula, just making a point)
6" 0x --> 6" 1x --> 6" 2x --> 18" 4x
Well, heck, try skipping the 1x and going straight from 0x to 2x. Could split it evenly and go
9" 0x --> 9" 2x --> 18" 4x
Or I often just error on the side of softer, you can always shorten the tippet later if its too soft for the casts you need
6" 0x --> 12" 2x --> 18" 4x