A very stable example would feature resolution to the G# over the E chord (the major 3rd), shifting its placement within the bar away from the stronger beats adds an element of instability to the same phrase. Replacing our final G# note with an A or B leads the ear to crave resolution in the phrases which follow.
Resolving our lines from the 4th to the 3rd of the chord. By hanging on the 4th degree longer we add anticipation and, again, some tension. Varying the same melody by changing the stable points is a great melodic tool.
Adding the blue note will bring in a certain subtle tension to each line too.
Shifting the timing/beat placement of the second lick or phrase in solo will set up a feeling that the listener wants to ‘hear whats coming next’.
Setting the ‘story’ of your solo with stable phrases resolved on the stronger beats of the bar, then introducing instability, before resolving your solo on the safer/stable phrasing gives a sense of completion and structure.