We are working on revamping our scouting this year however things that have worked well in the past for us include,
.Having one scout per robot on the field
-Have the scout record what points each robot individually contributed to their alliance.
-Record what deffences each robot can AND can't tackle
-Have a section in whatever form of scouting you use, whether that be electronic or paper, where the scout can write a note about that robot for each match (the note could be anything from robot didn't move to, the drivers were lacking practice/coordination)
.Having a picture of every robot while they're on the field (we find it easier to identify a robot when its on the open field than when its crammed up in a tiny pit area)
.Pit scouting is useful, but it can only go so far (generally speaking most people you speak to in the pit are going to give you a sales pitch as to why you should pick them)
Once we have the scouting info from the first day of qualifications, We will spend the majority of that night with the team captain(s), drivers and scout team to work at a preliminary pick list. This lets us know which robots to keep a sharp eye on throughout the rest of qualifications. If a drastic change happens such as a robot starting to seriously malfunction, we can adjust our pick list accordingly.
Also note that having a plan laid out for what to do if your team gets picked is a really good idea.