For storage I use Avent storage cups - they are clear with blue lids. I think they are about $1 each but you can reuse them over and over again which is great and they also come with this adaptor that fits onto some pumps and you can express straight into the storage cup.

With steralising, I am a bit psycho and steralise each time I want to use the pump. I just use it and then put it back in the steamer and just take the lid off when I want to use it again. I know steralising isn't recommended anymore but because I am expressing mostly at the office, this is what works best for me.

I also freeze EBM within 2 days of collection together and haven't found any dramas.