Stick to the basics before birth then but as you need afterwards to avoid wasting money.
Essentials (IMO)
Travel: lie flat pushchair and/or sling, group 0+ car seat
Sleep: Moses basket and/or cot, matress, 3x sheets, 2x small cellular blankets
Small blankets are easier to use without swamping baby, learning to swaddle was an essential skill for us.
Feeding: boobs and/or bottles, steriliser, 12x muslins (minimimum)
Muslins can be used for almost anything and make great bibs as they are big. Try formula in hospital if they provide and find one that suits then get DP to pick up a carton.
Bathing/changing: travel change mat, cotton wool pads and/or wipes, pack of nappies in each newborn size.
Don't stock up on lots of nappies because you may find size 1/2 doesn't fit for long or at all if you have a big baby. Ditto wipes as some brands can cause reactions on babies sensitive skin.
Clothing: 8x babygros, 8x vests, 3x cardigans, 2x hats and 2x mitts.
I generally buy newborn as a starting point as I think its the most universal size but you can always get someone to pick up a different size if required.