Using the GTS to Trade With Yourself Using Only One System

This is...more than slightly off-topic for a competitive Pokémon battling blog, but people have found it to be very helpful in the past, so I'll put it up here as well. This is how you can trade Pokémon with yourself through the GTS in order to have certain Pokémon evolve; be it through trading, like with Machoke, Kadabra, Haunter...or while trading with a held item, like for Seadra, Rhydon, or Clamperl. Obviously, there are more Pokémon that meet these criteria, but I'm not going to list them all off. For the sake of simplicity, I will be using Pokémon X & Y as my example games, though you could theoretically do this with any game that uses the GTS, provided that the GTS function has not been discontinued.

So, what do you need?
- A 3DS
- Two copies of Pokémon X & Y (be it yours and a friend's, or if you're one of those people who, like me, own both X and Y)
- A Pokémon you want to evolve through trading
- An extra "junk" Pokémon
- An Internet connection
- Approximately 10-15 minutes

NOTE: I am calling the "junk" Pokémon "junk" because of the fact that this Pokémon should be of a species that is fairly common in the wild as to prevent trading mishaps. The term is not to be taken to mean that the Pokémon is considered to be junk-like, as no Pokémon is.
Final note: Do NOT upload the Pokémon you are trading for evolution under any circumstance, particularly if it is shiny! You do not want to lose the Pokémon. Always upload the extra Pokémon. This will prevent trading mishaps. 

So, onto the real tutorial:
1. Determine which Pokémon you want to evolve and make sure that you are meeting the correct criteria for its evolution.
2. Switch cartridges.
3. Catch (or grab from a Box) your junk Pokémon. You can put them in your party or in a Box; personally, I like keeping the Trapinch I use for this in my party in Pokémon X when I do this, just because I find it a little bit easier to stick the beast I traded for the Trapinch back into the GTS.
4. Upload the junk Pokémon to the GTS and set the trade condition to the unevolved Pokémon you plan to trade from the other game. Set your trading message to "Trading w/ myself," as you have just enough characters to do so, and it may discourage others from trading.
5. Switch cartridges.
6. Go into the GTS and find your other profile; it will likely be the first one under the Pokémon you deposited (search by name). Select it and trade with yourself.
7. Re-upload the junk Pokémon you just got from the trade, with the trade condition being the name of the now-evolved Pokémon (you can use the name entry if it's not already in your Pokédex; just make sure you've spelled it correctly). Set your trading message to "Trading w/ myself" on this game, as well, if you have not already done so.
8. Switch cartridges.
9. Go into the GTS and receive the Pokémon from the other game. It should-- provided that you've done everything correctly-- evolve.
10. Search for your junk Pokémon, and trade the now-evolved Pokémon so that you get the junk Pokémon into the game it is originally from.
11. Switch cartridges.
12. Go into the GTS a final time and receive the now-evolved form of the Pokémon. At this point, your original Pokémon should have evolved, and the junk Pokémon should be back on the game it is originally from.

I know it seems confusing. It takes longer to do the first time you do it; it took me ~15-20 minutes the first time, but less than 10 minutes the second time. I hope this is helpful to someone, and will hopefully go on and post another, more battling-relevant post soon.