To invert any chord, just take the bottom note and move it to the top, or take the top note and move it to the bottom. Here is an example:
C7 chord inversions going forward
root position: C-E-G-Bb
1st inversion: E-G-Bb-C
2nd inversion: G-Bb-C-E
3rd inversion: Bb-C-E-G
Cm7 inversions going backward
root position: C-E-G-Bb
3rd inversion: Bb-C-E-G
2nd inversion: G-Bb-C-E
1st inversion: E-G-Bb-C
To anwer your question, the easiest way to invert a chord is to go the inversion closest to where you are at the time.
