Creating a Modpack With Technic:

Step 1. Go To http://www.technicpack.net And download the launcher.

Step 2. Download the Vanilla Pack for whichever version you wish to create a modpack for.

Step 3. If you downloaded launcher to default path on Windows, do Window Key + R (Run) and type %APPDATA% go into .technic>modpacks>vanilla>bin (if not in appdata, just get to the same directory relative to where you downloaded it)

Step 4. Go To http://files.minecraftforge.net/maven/net/minecraftforge/forge/ and select the appropriate version and download the recommended universal file

Step 5. Get that file which you just downloaded, and rename it to "modpack" and place it into the bin folder that you should have open

Step 6. Now you need to gather the mods for your pack, go to a trusted site (personally I use http://www.9minecraft.net/) and place the mods into the mods folder.

Step 7. Run the pack, this may take some trial and error, considering certain mods may be incompatible, also make sure all the mods are the correct version and all the core-mods are present.

(Continue only if you wish to publish the modpack)

Step 8. Once you have all the kinks worked out and the modpack runs smoothly, make a copy of all the contents of the Vanilla file, remove all the files not in their own folders, so all the .txt, .json, .dat files, also remove the minecraft.jar file from the bin as well as the config folder, (this is so when someone else downloads your pack that it will be a fresh install and that they can configure it themselves unless you want to have specific configs for an RPG pack for instance ex. Crash Landing)

Step 9. Put all the files into a .zip file named correctly with what you want to call your pack, (ex. If modpack name is Hillbilly Adventure 42" it would be "hillbilly-adventure-42-1.0") and upload it to a file holding server, I recommend Dropbox (it's free), and get a share link.

Step 10. Make sure you have an account with Technic, and upload the modpack, filling out all the appropriate fields and other data, when you put the share link make sure to change the 0 at the end to a 1, which means that whomever downloads will not need permissions. Then publish, and presto, you have a modpack. (you should make sure the pack works, try downloading it, and testing it, make sure to fix any errors)