I use MagicLauncher as well but installing Forge for Minecraft 1.6.2 is now super easy you just have to know what your doing to make it work. I'll give you detailed instuction on how to install forge and other mods that go with it.
Next go to where the installer is downloaded at (for windows users only) right click on it and then click on open with then click on choose default program. A window will pop up just click on use program from computer. A new window will open now look for Java™ Platform SE Binary and click on okay. (Note this only has to be done ones after this all future forge build will open when clicked on.)
Now open the launcher make sure client is selected and click on run. Now just open the new default launcher that was relesed for Minecraft 1.6. Next to profile if it shows (Default) click on it and select Forge. Now just log into Minecraft with the default launcher. This will allow Forge to install without any need to manually edit Minecraft. Once Minecraft loads you can save and quite.
On to Magic Launcher. Open it up and click on setup. Look for Environment and click on it a drop down list with open and you can now select Forge 220.127.116.119. This is the modified Jar file you just installed with the default lancher. Under Mods all you have to install here is Optifile and/or any mod that would normally go in the jar. All other mods go in the External Mods list.
If you are using Optifine you must first click on Advanced Tab and under Parameters past this line of text -Dfml.ignorePatchDiscrepancies=true
Yes the - is part of what needs to be copied. If you don't add this then Minecraft will crash or textures will not load right.
Now for adding any mods go back to Mods tab and next to External Mods click on Manage. This will allow you to install all the mods you want to use. I'll use TreeCapitator as an example for this part becuase it needs a core mod. Thanks to 1.6.2 build of Forge now all core mods go into the mods folder (External Mods section for Magic Launcher) So download bspkrsCore latest and TreeCapitator Forge build. Move this mods into the window that opened up when you click on manage.
Now you can add other mods if you wish you don't have to use TreeCapitator it was just a good example. Now you can run Minecraft with mods in Magic Launcher. Just note that its still best to install mods one at a time. If you don't load Minecraft with MagicLauncher after each time you add a mod it could come back to bite you because you won't know what mod is causing a crash or is incompatible with each other.
I know a long process but it works and once you do it the first time you will understand just how much easier and faster it is to install Forge Mods. Just note that for some reason Risugami's Mods will not work with Forge.even though Forge has had its own version of modloader for some time now.
Anyways hopes this helps. Happy modding. \o.
EDIT: I forgot to note that with the changes to Forge and how its installed when using Magic Launcher that you will see it say No modloader, No Forge, or No Mods Found. The changes to both Forge and Minecraft will make this show up but don't worry all the mods stull work and will show that the mods are installed once you click on Mods from the Minecraft Main Menu in game.
Uhh, wrong, I tried installing forge and modloader many times using maic launcher, but they both just make my game crash, I have looked up OVER 9,000 tutorials hoping to find one that works, but none are working.
Ugh, guys we are feeding a troll, can't you see that the OP did not even reply to his own thread yet? Anyways, there are literally only 2-3 mods that don't need any API, modding is just mind blowing without these APIs.
There is 2 versions, Forge and Non-Forge. So you kind of look REAAAALLYY stupid
Ok, I looked into it and YES. YOU WIN. There are two versions of the too many items mod. one that requires forge and one that doesn't. I GUESS THE LINK I CLICKED REQUIRED FORGE. So I've been looking more into this whole "no forge or modloader" thing, and I think I got a good list. Shape shifter Z, a mod that lets you turn into mobs and gain their abilities. Single player commands, a mod that adds dozens of more commands and I think another mob (try typing "spawn giant"). TOO MANY ITEMS, an ingame version of INVedit, though efficient, it's max value for enchantments is 10, while INVedit has no max. Optifine, I'm too lazy to find out what it does but apparently it doesn't need forge or modloader. INVedit, pretty much a tool to edit your inventory. It's not ingame, so you have to open a completely different program to use. HOWEVER, it has an enchantment tab which is the only thing it has that's better than too many items. You can use this tab to, if you want, give your diamond sword a 1000 level sharpness enchantment. Too many items can do this too, but the maximum enchantment it will give your item is level 10. I think that's about it, but I'm pretty sure I saw some others so I will look into it some more.
I'm actually really curious about this myself. It took me forever to get Optifine and SEUS running well on 1.5.2 and I'm really curious about installing Forge so I can try out some of these great mods (mainly Millenaire and one of the extra biomes modes) but everywhere I look I see that Forge does NOT play nice with Optifine.
Does anyone have a reliable way to make Forge work with Optifine in 1.5.2? I've searched many places, including Youtube, but every single tutorial has comments from people who say that the procedure didn't work and they had to reinstall everything.