i was to gamescom, one of the big three game conventions (the others being TGs ans E3),i dunno much about TGS, but there's always basics:
-if you're going only one day, get a hall plan (you don't want to go there first and then search for a hall and exhibitor plan) and set priorities an what you want to see the most (since you might have to sacrifice multiple things you want less for one thing you want to see more, or the other way around).
-be prepared to queue for hours, so you don't want to lose tme on not queuing!
take you own food and drinks, saves you both time and money (srsly, con food be like, 10€ for a slice of sub-par pizza).
-if you're not there for looting trash, don't go near the stages where they just throw freebies, 99% of them are not worth your time, if the stage has something alse to offer, that you want to see, hear etc. it's fine, but there are exhibitors that d just hire some jerk and sparsely clothed ladies to throw out freebies with their advertisement.
-if possible, combine watching the big presentations (those you don't have to queue for) with queueing for "closed" presentations or hands-on game demos.
-if you're not too heavily packed and don't like sittig on the floor or standing all the time, take a small, light camping chair with you (the three-legged type are the smallest). i usually don't since i don't mind sitting on the floor.
i seriouslyhave no idea how the tokyo game show looks like, but gamescom is best if you go on at least 3 days, so you don't have to rush through everything and can have a nicer, or more relaxed con experience and also "waste" some time on things like games you never heard about, which turn out to look intersting, watch people (cosplayers, weirdos etc.), have a chat with indie developers, just stroll around, make photos, or check out the shopping stalls (although most have inflated prices, but the official manufacturer's/developer's/publisher's stalls tend to have at least rrp-niveau).