LSAT score and GPA are "hard" data. Softs refer to everything in your application that isn't "hard" data.
Softs are inherently unquantifiable. That's why they're called softs.
The tiers below are very rough guidelines for putting a number on something that really can't be quantified. Don't take the tiers too seriously when comparing yourself to other applicants on LSData. Holistically valuing softs is the admissions committee's job.
Tier 1 (extremely rare)
Tier 2 (rare)
Tier 3 (uncommon)
Tier 4 (common)