Most retail pricing follows seasons rather than moods. Inventory arrives, sells at full price for a while, and then makes room for whatever comes next. Once you see purchasing as a calendar problem, patience becomes a strategy rather than a chore.
Seasonal goods are the clearest example. Outdoor gear, warm-weather clothing and garden equipment tend to be discounted once their season is ending, not while demand is peaking. Buying slightly out of step with the crowd usually costs less and involves far less competition for stock.
Electronics follow product cycles instead of weather. When a manufacturer announces a successor, the outgoing model often becomes markedly better value while remaining perfectly capable. If you are not chasing the newest specification, tracking release schedules is more useful than tracking sale banners.
Home and furniture categories tend to shift around inventory resets, when floor models and discontinued finishes are cleared out. Travel behaves differently again, rewarding flexibility over timing: shifting a trip by a few days often changes the price more than booking on a supposedly perfect date.
None of this requires spreadsheets. Keeping a short list of things you intend to buy eventually, and letting the calendar come to you, is enough to change what you spend across a year.