If you don't take indoor shots much, a flash would be useless. If you don't do macro shots, a micro lens would be useless. Likewise if you don't do long exposure shots or take group pictures with yourself in it, a tripod will be pretty useless too...
So you have to see what you need and buy accordingly...
Don't buy a macro lens for the sake of buying one. Try closeup filters for the kit lens, because that gets closer. You have to think how often you'd use the macro (usually a prime lens) A nice prime lens would be nice like a 50mm f1.4 or a sigma 30mm f1.4. Low light photography.
Tripod isn't especially fun to lug around IMO. What of your gear is restricting you now?
go take more picture and find what you like then buy equipment which can help you on what you like.
if you take lots of portrait and you like natural lights and not flash then some fast primes (or zoom if you got the $$$) will be next.
if you want to do wedding photo business, a good flash and external battery will help.
if you are one of those who got tons of patience (and time) to hunt for spider and other creepy crawlers then get a macro lense.
if you are a control freak then invest in studio equipment and soft box
er .. wan to consider dry box also to protect your investment from fungus?