A fair number of people I know have a great deal of trouble keeping track of small personal effects: wallets, sunglasses, keys, and the like. When they encounter someone who does not have this problem, they assume it’s because of some inherent superiority of memory. In my experience, this is not the case. What differs between those who lose things and those who do not is the degree to which they are systematic.
The first vital aspect of being systematic is to maintain consistency in where things are placed. One’s keys should always be in the same pocket when out or at work, and always on the same table of shelf when at home. One’s gloves should likewise always be kept in the same place, at least during seasons when they are required, and moved to a consistent but less accessible place during the summer. All this is made dramatically easier by choosing clothes with a similar array of pockets. Having a single jacket with lots of pockets is an enormous boon: I always know that my wallet is in the right-side breast pocket, while my camera is in the left. The small sub-pocket under that holds a four-colour pen. The inside left pocket has a pair of liner gloves, while the inside right pocket has an iPod Shuffle and space for valuable things carried rarely. Having a consistently used bag with lots of pockets is similarly useful.
Trust, but verify
The second vital aspect is frequent auditing. If you have followed the advice of using the same pockets at all times, this will soon become automatic and second nature. You learn to be intuitively aware of the presence or absence of objects from their designated spaces. If they are not there, you know to seek them out immediately and return them to their designated position.
Never trust yourself to remember a deviation from the system. Moving something into the wrong place – perhaps to make it more convenient to carry something else – will only produce anxiety while you are tying to remember the deviation and frustration when it leads to things being misplaced or not immediately accessible.
Fashion is your enemy
The real trouble begins when you have a wardrobe that has dramatically different elements: trousers with no pockets, multiple jackets, purses with differing internal compositions. For those who insist on such variety, I can offer no aid. Unless your memory is much better than mine, you are probably doomed to lose things relatively often.
Some level of variety must certainly be dealt with by anyone, and this can be accomplished by having a number of set collections of gear with defined associated positions. One might have a ‘no jacket because it is sunny out, still carrying photographic gear’ option, as well as an ‘out biking in the countryside, repair tools required’ configuration. In my experience, it is feasible to maintain a good number, provided they are as similar as possible (wallet always on the same side, non-included items left in defined positions at home) and they are always identically configured. Objects only carried rarely are by far the easiest to lose. I virtually never carry an umbrella (preferring to rely on waterproof clothing), so I constantly forget them when I have been carrying one for whatever reason.
Naturally, there are plenty of people for whom the above is too much work for too little value. The point is less to convince people that they should or should not adopt such a system and more to argue that losing or not losing objects is a reflection of planning and habit, rather than inherent cognitive characteristics. That said, a certain fascination with gear and a somewhat compulsive nature certainly help in the initial development and constant refinement of such an order.