Try not to worry if your baby spends the day dressed in a babygro (onesie.) I used to fret about this, that my son didn't look "properly dressed." But who cares? Several months down the line I don't. And I wish I'd done it more often.
Don't be too quick to wish their babyhood away - savour each phase before they hit the next. Smile when they learn to crawl, laugh and cheer with them when they begin to pull themselves up onto the furniture and do you know what? It's okay to shed a little tear when they begin to walk, not least because they will drive you crazy with how much more they can do!
Let them feed themselves - at least once in their babyhood. It will be very, very messy (and your OCD-meter might go off the charts with the mess) but it is also very, very good for them.
Bath time is a baby's playground. It will cause you to go into complete melt down mode as they go after everything at their eye level...just baby proof the bath and enjoy bath time.
Have at least one 'run and grab camera' moments before you help them out of a tricky position they've got themselves into ;).
Enjoy the babyhood. The chubby cheeks. The blue eyes. The soul-searching looks they will give you. Even those late night snuggles.
Play with hats often. They might begin to hate wearing hats.
Let Granny get a look-in. Even if you have to squash any paranoid thoughts. Unless she's a reckless child carer she will bring a calm to your new motherhood that you can't culture until you've been there and done the whole hog of motherhood.
Indulge their cheeky tendencies every now and then. And try to find new ways of saying 'no' without actually saying no ;).
Also, buy the best camera your budget will stretch too. These memories and moments are precious and are worth capturing so you can have them in your family for generations to come.