I have a fairly detailed and elaborate way of keeping wish lists, so please don't laugh
I write them in a little journal dedicated to my clothes maintainance, where I also write down packing lists for trips, list for stuff to be taken to the tailor, favorite outfits combos, interesting things to try and so on.
I have two lists for every season; one is for stuff I'd like to find (e.g. I want a purple 32" long boyfriend cardigan) and the other one is for actual items I have seen in stores or online that I'm coveting. Of course the more the two overlap, the better.
Within every list I categorize stuff on couple of different criteria. One is how much I need/like something. For example, I really need a new umbrella, while I'd love to have a brown leather jacket but since I already have a black one I can do without the brown till I find "the one". The second criterion is how much
I'm willing to spend on something. Here stuff get divided into low- up to $50 ( e.g. a basic layering jersey turtleneck), mid ( $50-$100) and high (>$100) range, such as designer jeans . These is usually closely correlated with the trendiness of the item, the really trendy stuff ( such as ombre full skirt I got this summer) go into the lower, the in-between stuff ( a grey cowlneck sweater I got last winter, grey and cowl were very in, but the item is wearable later too) goes into the middle range, while only more timeless pieces (such as outerwear, boots, jeans, cashmere sweaters) get allowed to fit in the high cost range. Of course items are also divided by groups, such as tops, bottoms, shoes, accessories and so on.
This sounds like a lot of work, but a allows for a quick decision on whether I should buy something at that moment or not. It also helps me keep track of stuff; for example, on my current wish list there are four (!) purple items to be worn over skinnies; the first list has a long purple boyfriend cardigan and a LS purple shirtdress; the second list has a purple Sweat Pea mesh tunic and a Boden long purple vest. Of course, it would be silly to get all the four, I'll get one, two at most, depending on what I find and current prices
The list gets constantly edited, as I find/buy stuff or decide I do not need something after all.