Score independently. Form a holistic view only after every cell is filled.
Set up the rubric first: name your decision, list the alternatives across the top, define the attributes that matter, and write anchor descriptions for what a 1, 3, and 5 score looks like on each attribute. Anchors should be concrete and observable — "consistently exceeds expectations on X" is better than "good at X."
Then score. One attribute at a time, across all alternatives, before moving on. Resist the urge to check your scores against your overall view until the grid is complete. Your changes save automatically. Use Export to download a saved copy you can reload later, or Copy as Table to paste a record into your notes.