Over the last several posts, this blog has laid before you three methods, each of which joins two colors of yarn AND works in the tails "as you go"
(or life, for that matter) there are advantages and disadvantages--and you must make up your own mind. The Russian join is probably the least favorable--it's hard to make the join come out just where it should, ripping back to add stitches is very difficult, and this join is S*L*O*W.
The back join is more flexible than the Russian join, is faster, and accomplishes the same result. The back join can be modified so it is not quite as bulky as the Russian join.
The overcast method is not bulky, and it is fast, but because the tails aren't folded into the fabric itself with the overcast method, there is less "friction" holding in the tails. The overcast method is not only more delicate-looking, it is actually more delicate--more likely to pull loose than the Russian join or the back join.
It will have occured to you that it is possible to combine methods. A good thing to do in cotton, linen, acrylic or another slippery yarn is to start 8 or 10 stitches away from the join-point, overcast the old yarn to within 3 stitches of the join point, do 3 stitches of back join in the old color, 3 stitches of the back join in the new color, and then 6 or so stitches of overcast in the new color to finish up. (This one WILL hold!)
I like the overcast method in a hairy, thin yarn, like a Shetland wool, (thanks, Ysolda for the link). In this sort of super-holding yarn, tails can be expected to get all the traction required to pin them down from the surrounding stitches, without having to be actually knitted onto the fabric face. And, for thin stripes in thin fabric, like socks, the advantage of not having doubled stitches on the fabric face outweighs the downside of the join being more delicate, at least to my mind.
As the old folks used to say: "you pays your money, and you takes your choice" (but, a swatch will reveal much).
(You have been reading TECHknitting on: the overcast method for joining yarns in multi-color knitting.)