I hail from Langwarrin...on the way to Phillip Island via the South-Eastern, but you get to turn off before Hastings (PHEW!) and we have LOTS of op-shops. When I lived in Seaford, my local was a very average place with lots of second-hand cheap clothes and the occasional random silk kimono. And terrible books.
Now I call Frankston my local... cos there's HEAPS of variety and not a little quality. Of course, Savers is a good place to start. Once you've thoroughly (and that can take an hour. Maybe two.) searched their racks, you should walk out with minimum one pair jeans (Bettina Liano floats my boat, but I've stumbled across the occasional pair of sass&bide's and mavi and lee and....yeah, ok) a skirt (lots of choice, all $5.99 unless otherwise tagged) and some books. I read a LOT. Then, head over to the Red Cross shop. They get a lot of new and ex-shop stock. One day and girlfriend and I were trapped. We spent a hundred bucks between the two of us and left with about $800 RRP worth of dresses. If you don't mind a few tiny (seriously tiny) repairs, this shop can be your best friend. Two doors down is the Brotherhood store. Can be very hit and miss, but I've found some wonderful seventies' dresses here and boots that I will love until I die. On the back side of Quayside...a tiny tired little shop has lots of jumpers. Well, that's how it always seems. on the station side of Quayside three more shops sit in close proximity. One's pretty new and has TONS of cheapie stuff (and maternity, last time I was in. ) One's got good books, and the other ...you never know. I think that's my favorite thing about op-shopping (other than the thrill of getting a bargain, like the breast pump below!) ... it takes determination and effort, but the random rewards are great.
Further down the Peninsula...Mount Eliza has three op-shops, all of which have great potential. I don't think I've ever returned home empty-handed after a sojourn there. Of course, it's also the suburb of hairdressers, so you can kill two birds with one stone! A little further down... Mornington is not the op-shoppers' best friend, but you can start at one end of the Main Street with St.Peter's Church op-shop, walk most of the way up to another, cross over and visit the Animal Aid op-shop ...then have a great lunch before you get back in your car. Where else???
Rosebud has a lovely big place that is always good for books. Blairgowrie has another big place with lots of tee-shirts (well, usually) and Sorrento has two op-shops which I visit on a weekly basis and never come away from empty-handed. Someone down there must be a proof-reader, because I keep finding uncorrected proofs and getting to read them well ahead of their release dates! So... in the area? go op-shopping! Hope I'm not boring you all....