I had a double mastectomy in 2017 and these were things I found helpful. I was given two cloth drain bags by my breastcare nurse...basically two shopping type or library books bags. I never used them however, as I just popped my drains into my dressing gown pockets so I didn't have to carry them. Button down the front nighties or pyjamas...not silk as you'll slide down the bed. Dressing gown with two large pockets, slippers that were easy to put on without having to use a finger at the heel to get on. They must be non slip, or the nurses will not let you wear them...slip hazard. I found my kindle easier to hold in bed with one hand whilst lying down, and increasing the font size, meant I didn't have to wear my glasses. Easier to 'turn' the page too, with a finger tap. I took my knitting too. My own tea and coffee as hospital grade is yucky. I also took some cup o' soups for a change from tea. Some hard sweets, I took Werther's to keep my mouth moist. (My excuse...I have a sweet tooth). Bickford's Lime cordial as the bottled water at room temperature is very flat. Small change for the Pink Lady trolley and also the vending machine for midnight snacks. Eye drops as the aircon can dry your eyes out and also lip balm for the same reason. I wore a light pashmina type shawl as my bed was under the ceiling vent for the aircon. Long charger cords for phone and kindle. I'm sure others will add to this list. Good luck with your surgery, which for me, was remarkable little pain.