I usually shop Old Navy online and some Gap, when they are on sale and having discounts for my kids. Target has some cute clothes and shoes. I think almost all of my 3 year old's play shoes are from Target. Oh, and Kohl's has tons and tons of cute things. They have a lot of sales and things are frequently nicer items for 50% off. I get tights from Wal-mart and they hold up very nicely. For higher end stuff like Gymboree and Matilda Jane, I go to Facebook and shop their consignments. If you type in a search for those names you will get the Gymboree consignment stores, and Matilda Jane consignment.
For a strategy, l am going to assume the items you posted are the main pieces you will have in her wardrobe. I don't know what your weather is like, so I'll just use mine. It's cold here until well into May. So, I would definitely get some tights, I'm thinking at least 3 pairs, white/cream, pink, and gray. Get some basic layering tops too. I love the solid Tees from Old Navy, really soft and nice quality. Basic colors, white, cream and pink. I have 2 of each basic color. Also, Old Navy and Gap has cute graphic tees too, pick up at least 2 or 3 of those, they will be cute with the denim skirt and the blazer over top of them. You can add another cute skirt from ON, a pair of skinny jeans (they are not that tight from ON and really comfy), and a couple pairs of leggings. ON has awesome hoodie jackets too (1 or 2 of those). I stay away from cardi and such because my daughter is rough on her clothes (playdough, paint, markers,etc.) and they don't hold up as well to frequent washings.Can you tell I'm an ON and Gap fan? They are just so awesome for my kids. I have 4 kids and I wait for a sale and shop for all 4 of them online. I have a Gap card and earn reward points for their stuff. I like Gap stuff for me too, so it's a bonus. For accessories, I'd go to Wal-mart and get some cute bracelets and hair clips. You may want a couple of fancy party type dresses too and I'd go to Kohl's for those. Shoes, a pair of boots from Target, and maybe some "fun" shoes. I get Mary Janes and sneakers from Zappos in nice brands like SeeKaiRun and Pediped, but if I had a Stride rite I'd go there because you want a good fit. Once you have your basics, I'd look at the Gymbo and Matilda Jane or whatever other fancy name you like, maybe Hanna Anderson and get to the facebook consignments for a couple of dress/legging sets or dresses to add to the mix. Ok, so I've written you a book on how I shop for my kids, mostly my 2 little ones. I hope it helps a little, it's just how I do it.