I just caught a couple last night (while trying for a Coelacanth for my initiative!).
I agree with stitchmaker above, I like using the throwing beans to scare away shadows that I know are not it. Another trick you can use is the Save and Continue to refresh the bugs and fish that are currently...
Both June and Olive are adorable, it really depends on the vibe you're into I suppose?
For my town, I'd definitely go with Olive because I love having villagers with more 'natural' colourings, which currently is a lot of brown villagers, and Olive's grey would be a nice change.