Thanks to DMC’s Blog, I found a link to a delightful post on Creativepoppy.com on ways to use multi-colored threads. These tips are designed for Cross Stitch but they can be adapted to needlepoint easily.
Most of the instructions need you to do one stitch at a time, and with needlepoint this would also hold true. One technique, creating a blended look, has you completing the Cross Stitches in two passes. While this won’t happen with Tent Stitch, you can adapt this technique to any stitch that has layers or that can be done in two passes.
With a layered stitch, such as Rice, make the base Crosses in one pass and the ties in a second pass. With a stitch such as Criss-Cross Hungarian, make the Hungarians in one pass and the fill in crosses in another.
There are two other easy ways to create this blended effect. If you are using a multi-stranded threads, switch the direction of half the strands. This creates and already blended stitching thread. I used that technique for the background of this Needledeeva nativity figure.
A second option would be to use two different needles and to make units of the stitch with each needle alternately.
While I love multi-colored threads, often they can be hard to use in a piece. These tips make that easier.