Remember the post about tips for travel? It goes hand in hand with the section I forgot on dealing with your return. This isn't a very effective use for "spot the time traveler" either as if you follow the tips it can be very hard to do, as time travelers generally either don't stick out at all or draw so much attention it's too obvious to be believed.
Straight in to it you can expect massive headaches and severe dehydration after you return, keep aspirin and lots of water on hand. I haven't really noticed any substantial difference between using mineral water or purified water, I'm currently testing vitamin waters and sports drinks. You can expect random sweating for the following week and a strange burning smell which I haven't entirely figured out. Depending on when and where you travel you'll likely need a few good showers after you get back so I'd suggest some strong antibacterial soap and any additional stronger lye content soap you can find to remove a good layer of skin. The foreign bacteria has the potential to be an extremely serious problem if it gets out in the general public so I'd suggest a good full body scrub down as soon as you can manage after returning. When you come back make sure to follow the same rules as leaving, no public areas, structurally sound, away from any main roads, a clean change of appropriate clothes and anything to boost your immune system as it re-adjusts to the area which isn't so important if you're only gone a short time but if it's been a while it'll be just like going to a new place.
Sometimes you might have a hard time keeping food down and in this case it's more about nerves than anything making you sick. For this same reason sometimes uncontrollable hand tremors or other shaking may occur. Just to re-iterate from a previous post that time travel is an extremely violent process if it wasn't obvious enough already. Most symptoms go away after a week or two though thankfully. Other random or strange things may occur, once I cam back with grey hair that regained color after a day but in that day as it began to regain color it was changing colors at the ends at random. To my knowledge everything comes back in the same manner it left for the most part, no extra items or missing items so far though you never know what might happen. Sometimes you'll need to adjust for pressure or oxygen content if the air is thicker or thinner, usually the pressure isn't much more than popping your ears for which some gum may help. The reason I say usually is one time I remember coming through in a high pressure environment and the sudden change was as you can imagine less than pleasant, and I could easily imagine that had it gone the opposite way I might have had an explosive decompression scenario on my hands and I'm not exactly eager to find out how that would have ended.
It's hard to list everything as there aren't many constants the idea I suppose really is to just be ready for the consequences whatever they may be. One thing other than headaches and thirst that I noticed to be almost constant to every trip is ringing in my ears other than compression and sometimes it can be very painful, it's not loud or quiet it's hard to explain I suppose but it doesn't distort any incoming noise it's parallel to it. The good part is all this seems to be put on hold until you return. It's rare to have any of these things happen going in to a trip which is nice, though remember other posts for what to expect going in, however keep in mind when you return you'll wish you hadn't.
Last thing to mention is this only occurs with actual travel, stopping time or traveling locally like within one day in the same city generally don't have these kinds of results or if they do then they're substantially less serious by comparison. Also don't freak out if you skin feels a little oily or has a slight residue as I can assure you it's perfectly harmless, though it'd still be best if you remove it as quickly as you can, as it can be quite uncomfortable to try and go about regular business with it on you. If you're having a hard time removing it for any reason I've noticed acetone does wonders at drying it out and making it much easier to remove often it will flake away.
Hope you find this useful, and if you've already traveled and are cursing me for not telling you about this to begin with just keep in mind I'd previously warned you it was a violent process which should've indicated there's a good chance for consequences, and at least now you know.
Remember that reality is only perception and is therefore subjective and malleable if you can picture it you can make it happen.