You can put multiple levels worth of IVs in, so if you catch it at low (or high) level you can put it's stats in at that level and then enter it in the Battle Subway and plug in it's level 50 stats.
That said, I find that anything above level 40 has high enough stats to get a range accurate enough for RNG Reporter to find the seed you hit. You'll get a range, obviously, not the exact IVs, but you can plug a range into the DS Parameters Search window anyways.
Also, the pokecheck website can show you your IVs as well with perfect accuracy. That requires saving, though, so takes longer than just plugging it into a calculator imo.
As for synchronizers, I imagine most just use the ones they have until they need a new one and then breed or catch the one they need. If you're bored, though, feel free to breed a whole box of 'em. =)
Another thing I forgot to mention is before you can use RNG Reporter to find shinies you will need to know your trainer ID and your secret ID. The TID is easy, it's on every pokemon you've caught, but the SID is harder to get. I... actually don't know how to find it except to use the pokecheck website. If you're not okay with using pokecheck, you might want to ask the RNG thread how to find your SID without it. RNG Reporter will still work without it, you just cannot use it to find shinies because shininess is determined by an interaction between the mon's personal ID (or PID) and your TID and SID. If you are okay with using pokecheck, just follow the instructions on their site and upload any pokemon you've caught and it'll be available for viewing. I use pokecheck a lot because it also displays the mon's PID and knowing the PID can really help to diagnose what went wrong with PID manipulation.
So the formula goes: DS Mac Address + encryption settings + the time you boot the cartridge = the seed you get. If you get the same seed, the same events happen in-game. With knowledge of how seeds translate into events, we can figure out in which seeds the event we want will occur and then backwards engineer what time we need to boot the cartridge to get that seed and, therefore, get that 'random' event. That is, in essence, the goal of RNG abuse.
- Tenth, repeat steps 2-9 again. And again. Keep repeating them until the DS Parameter Finder tells you a different result for Timer0. Every cartridge has TWO Timer0s, and when you boot the cart up which Timer0 you get is random. When you get a different Timer0, you get a different seed. Knowing both your Timer0s will help you, for one, figure out which is the more common so you can prefer seeds that need that Timer0 and, for two, will double the amount of seeds you can find in the event that you're looking for an extremely rare seed (such as a low frame shiny with exact IVs).
Once you have your encryption settings, your MAC Address, and the pokemon listed above you are ready to rumble and start RNG'ing.
- Seventh, check it's IVs. Don't need to be exact, a range is fine.
- Eighth, open up RNG Reporter and select 'DS Parameters Search' on the main screen. Fill as much of the screen out as you can -- plug the range of the IVs of the 'mon you just caught in, plug in the time you booted the cartridge at, select the correct version, put your mac address in, etc. Leave the VCount / Timer0 / GxStat / VFrame default.
- Ninth, the RNG Reporter will then use the IVs you input to figure out which seed you hit and will then us that along with your DS's MAC Address to backwards engineer which encryption settings your cartridge has. Assuming everything works out, it should spit out a single result at the bottom of the screen. Write down your VCount, GxStat, VFrame and Timer0 -- these are those encryption settings, and along with your MAC Address and the boot time they determine which seed you get when you boot your cartridge.
- First, go into the Wi-Fi settings on either the main menu or by selecting 'Online' on the C-Gear and then pressing the button that looks like a hammer and wrench. Go through the menu until you find your DS's MAC Address. Write this down.
-- This picture shows how to do this better: http://dl.dropbox.com/u/12206225/RNG/dmemaclocation.png
- Second, go to somewhere with high level pokemon like Victory Road and save.
- Third, hard reset your DS. Make sure you've got it so it doesn't automatically boot the cartridge -- you will need to sit on the entry screen until the right timer rolls around.
- Fourth, note the time and date on the DS. Then, wait until the seconds hand strikes 59 and press A, causing it to boot the cartridge.
- Fifth, get into the game. When it asks you if you want to turn the C-Gear on when loading the game, TELL IT NO. Never turn the C-Gear on when doing standard seed abuse; it WILL change your seed.
Before you begin, you should get the following things lined up:
- Two Chatots that know the move Chatter.
- A pokemon that knows Sweet Scent.
- A pokemon that can sleep and False Swipe (you can use two, but sometimes when RNG'ing you can be very short on party space so it helps to have one mon do it all)
- Synchronizers are very helpful, get one for each nature you like.
- Knowledge of how to check IVs on a pokemon.
- The program RNG Reporter downloaded and installed.
- A DS Phat or DS Lite. You cannot use standard seed abuse on DSi's and 3DS's. You can do C-Gear abuse, but that is 10x harder and you can't get shinies from it.
The first thing you're going to need to do before you start RNG'ing is to find your encryption settings. These settings are unique to your cart and your DS and they along with the time you boot the cartridge up are used to determine which seed you get.