I had issues with the dreaded 'v' in my cross-cuts for a long time. I asked one of the employees at my LQS (who is an excellent quilter and teaches their binding class). What she demo'd for me was to take your piece of fabric, folded selvage to selvage and hang it in front of you. Wiggle it sort of side-to-side to get any 'poofiness' (my term, not hers) / bubbles out of the hanging fabric. This helps to ensure that your fabric is 'on grain'.
For me, I find this works best with pre-washed fabric as you don't have the manufacturer's pressed fold and it makes the piece flexible and easier to find that 'on grain' appearance. I then lay that mostly straight piece of fabric on my ironing surface (I use my cutting table with towels as an ironing surface) and smooth the fabric from the fold to the selvage as well as the cut edges until it lays flat. I then press the folded edge. I don't care if the selvages line up - they generally won't. I then move the piece to my cutting mat and line my ruler exactly square on the folded edge. Trim off the uneven side and then measure my cuts from there.
Since I've been using this process - truly no more 'v' in my strips!