Birthday– never forget a girls birthday because it’s so obvious that it’s important to them. One thing that she won’t do is remind you that it’s her birthday. If you do forget then she will regard it as you don’t care and you just a waste of time.
Anniversaries– the first day that you guys met or started dating. That’s the most important day that shows the begging of your relationship. You don’t have to know it monthly but if it’s your first or second anniversary or even 5th it’s still important.
Their favourite colour– there is nothing worse than forgetting your girlfriend’s favourite colour and if she hates yellow and you get her something yellow, and she looks at you like an idiot or just lives it at the back of her closet to rest there.
Favourite spot to hang-out- where she likes being the most and have fun, whether it’s at her favourite restaurant or club. If you want to take her somewhere special or a place that she will enjoy, you need to know her favourite hangout place at least she will appreciate you taking her there and the fact you made the effort to make her happy.
Her favourite song– if she has one. There are some girls that love a certain song because it has a special meaning to them, even if you think it’s dumb it’s just sweet if you know or remember.