General rules

For Cello (Solo):

Repeated four-note scale patterns are a pain on cello. (1812 overture near the end)

Double stops up to a octave are usable throughout the range. 

Tenths start about from F# (minor) or G (major) (on the C string) as the lowest notes.

Repeated thirds involve a lot of shifting. best to do it in higher position for fast passages.

sustained triple stops require that some the upper notes be about an octave higher than the open string it's played on.

Fast multiple stops can get a bit clunky.

Fast alterations between natural harmonic and open string are impossible unless the left hand plucks after playing the harmonic

Forced harmonics are much more agile than either natural or artificial harmonics

Don't overuse the A string for solos. For some reason a lot of composers love it, but it just sounds to harsh especially in lower positions.

High position fifths are harder than sixths, thirds, octave, and tenths unless there is a chance to use the thumb (Shostakovich Cello concerto no. 1 first mvt. near the beginning)