Recently I suggested having some plainer items was a good way to wear the more unusual wardrobe orphans.
However another aspect occured to me and that's not having the right supporting pieces in particular underwear and footwear can mean you can't wear an item of clothing.
I think its a good idea to have your natural skintone (close in colour) some smooth bra and panties. These are good for wearing under light or slightly see through items.
I'm talking here about jersey tops with straps. They are great for keeping things underwraps when a neckline is a bit low or loose. The ones with adjustable straps allow you to adjust to the right level for you but the adjuster can be bumpy and uncomfortable in the wrong place. You can always shorten the straps yourself if you want a particular length.
I have these in lots of colours, but ivory, skintone and black would be a good start for lots of outfits.
Footwear can be really tricky for many people especially if you have plantar fasciitis (like me) or other foot problems. My approach here has been practicality with an eye to style.
So for example it is useful to have:-
Flat leather boots in long or short leg length, either black or your hair colour, these can help make skirts more wearable without heels.
I like metallic brogues which I wear with trousers when I want a bit more fun.
And I also have some metallic sandals which are still comfortable but can be worn in summer with dresses and skirts.