You can just play our basic blues, melodic, or harmonic minor scales.
Key of F: F, Ab, Bb, B, C, Eb, F.......Just going up and down..and you don't have to start on 1(F)
Melodic Minor, key of D: D, E, F, G, A, B, C#, D....same things, just go up and down in that scale...again, your starting point doesn't have to be on the 1(D)
Harmonic Minor, key of B: B, C#, D, E, F#, G, Bb, B...same thing again lol, just go up and down the scale and you don't have to start on 1(B)
Hope this helps, practice makes perfect!!