Here's what has worked for me: I keep a collection of images that I really like and that are realistic for my life and the way I like to dress. When I was young, I collected magazine pictures and catalog pages. Now I collect internet images on Pinterest. I also liked (and like) to draw my own ideas for outfits and silhouettes. Any of these collection methods (or combination of them) work. If drawing or collecting aren't appealing, try listing some favored silhouettes. Think about outfits that you already own that make you feel like you... or a silhouette you admired on a coworker or stranger on the street.
When I look at an image of an oversized sweater and jeans, I think to myself, "Yes, that's similar to my thrifted black cashmere sweater...and my thrifted, faded Levis." Maybe my pieces are different colors, but the silhouette will be similar. I will realize that another 7 or 8 pictures are really just that same silhouette and feel like I've got them covered. Another picture reminds me of my handmade indigo dress that I can wear with tights and my low boots. Maybe my dress is a slightly different shape, but the effect is similar. Most of the time, I've already been buying what I'm drawn to...and my pinned images confirm that I have what I need... already in my closet.
It is my guess that those of us who enjoy clothing already have pieces in our closets that would allow us to dress in our desired style. Maybe we're dabbling with a few different styles and that's OK. If we realize, however, that flares bug us or heels are not our favorites, then this is the time to focus the personal style and let them go (and remember not to buy them again). Keeping the number of pieces in our wardrobes limited allows us to have the pieces we want to wear at the ready. We don't have to wade through extra filler.
OK...so, bullet points:
1. Look at collected images of admired styles or list/sketch some admired silhouettes that fit with your lifestyle and the way you like to dress.
2. Decide on 2-3 preferred silhouettes.. or more, if that's your jive. :) (My examples were: big sweater + faded jeans... loose shift dresses + clogs or short boots... cocoon coat)
3. Think about color palette. Remember what just feels right in the mirror. (I know that soft oatmeal and white look nice with my skin + hair. Solids make me feel like me + calm + modern.)
4. Make outfits out of the clothes in your closet.
5. Wear them.
Box other pieces up and set them aside (to reassess at a later date) or let them go.
Yes, there may be a hole or two, where we find an item that we might like to buy. Since we are focusing on less, it is advisable to substitute something already in the closet for this item. Wearing and appreciating what we have is extremely informative and shopping palette cleansing. Keep a little list of what might be nice to buy, but don't rush out for it yet. If it is really necessary, thrift first. Consider making it next. Then consider buying fair.