Most users (including me!) have real issues with accurately getting to, and staying on, frequency with 2m WSPR. The WSPR slot is just 200Hz wide and the short-term and long-term rig drift can be a real problem. With WSJT-X v1.7 one can see most stations drifting wildly.
Last night I was greatly helped by David G0LRD who uses a GPS stabilised frequency reference, so he knows his frequency very accurately. He is also very strong with me, so I could see his signal clearly. All I had to do was net my rig so I was reporting to WSPRnet his correct frequency on RX. I did this late last night. My rig had to be set 20Hz low (144.488980MHz) to get G0LRD as close as possible. Of course, during the night I drifted off again, but in the short-term I knew I was on the correct window in the 2m band.
Longer term, the answer is a more accurate, and stable, frequency reference. Ideally this would be a GPS locked source. An accurate TCXO would be an affordable second best.
I was very grateful to G0LRD last night. Incidentally, David put up my 2m antenna some time ago. Kindness itself - thank you David!
I've now QSYed to 10m JT65 for the day.