Beware of complacency. My gf and I have been together nearly 5 years now, and it's easy for me to think "everything is fine, why change it?", but you will find all of a sudden that she has begun to get resentful of your laziness in the relationship and it will come out all at once if you leave it long enough.
Relationships require effort on both parts. The whole "spontaneity" thing is bang on. Even something as small as a bar of chocolate and a can of diet coke or flowers (this is specific to my gf btw) as a small "was thinking of you while I was out" gesture is good when you can't necessarily afford to take her out somewhere every week.
Activities beat "things" every time. Buy her some expensive thing, and she'll be happy for a day or two. Take her away for the weekend and she'll be much happier. She wants you, not stuff to buy you time to yourself.
If you need time to yourself, say that, but also consider whether you're being selfish with your time. I need an hour or two at my PC to game/unwind at the end of the day, but she's been by herself all day at home working so as much as I may want to chill out a bit, she needs some social activity more than I need to play some games. This may or may not apply to you. Suggesting you watch a movie together even if you don't feel like watching it is a good compromise.
Be good in bed. Read up on it if you have to. Try not to grope her too much in the beginning, because she'll develop a knee-jerk reaction to push you away that's hard to re-train (voice of experience!)! That makes it harder to initiate later on
Be her equal. This is the hardest part, I think (for me anyway). There are fine lines between being selfish dick, a pushover, and a respected peer in a relationship. LTRs are a long term power struggle, not an aggressive one, but there is always negotiation happening. It's hard to stand your ground without being a douche, and to compromise without losing respect. If you're naturally secure in yourself it won't be a problem, but if you overthink it then you could end up souring things or becoming a petty knob. The only advice I can suggest is to talk to friends (who aren't idiots) and test your feelings on tough situations to see if you might be wrong, or if something is actually unfair and worth bringing up with the other half.
Could all be the worst advice, but these are things that I've either done right or wrong over the years.