When the drop down appears with field names (like when you're typing in a WHERE clause), include a little icon for each field that's the first field in an index (like the key pic when it's the PK).

Being able to say "oh, that one has an index" would help me when trying to figure out how I want to filter things. (aka use "insertedtime" vs "posttime" vs the "start_time"). I'd say to use one icon (maybe greyed out) for non-clustered, and a different (or not greyed-out) icon for the clustered. You already include the field size, so why not this? Thanks!