I'm a uniform dresser. Summer is;
Jersey single breasted blazer
Various coloured jeggings plus indigo & black.
Various neutral tops.
Black boden hot pants 
Sandals.
Navy blazer goes with turquoise, pink, red, white jeggings.
Which goes with vest in navy/white/red.
So, navy blazer, white vest, pink jeggings. Or navy blazer, red top, turquoise jeggings. Any top except navy can be put with the shorts.
Jewellery is always diamonds from when we had money. No costume jewellery.
Nothing gets bought unless it matches something else. No quirky prints, no slogan t shirts.
Winter is several thermal tops shoved under a Barbour, jeggings, boots.
When we go away I can pack a weeks clothes into an overnight bag, Dh takes a huge suitcase. Usually the pink one so people think it's mine.
It's just a style you feel comfy in, in various co-ordinating colours. Pinterest helps, I researched lots of capsule wardrobes & adapted from there.