Some of you might know about the ARMA 3 launcher, but I think most don't from what I've heard. So here's a little tutorial on how to use it. There is no need to download anything as it's and BI/ARMA 3 original piece of software.
1. Navigate to your main ARMA 3 root folder (usually in C:\Program Files (x86)\Steam\steamapps\common\Arma 3) and find the little executable called arma3launcher.exe. I ran this once and then pinned it to the taskbar for easy access. You can also put a shortcut on your desktop or wherever you prefer. Run the arma3launcher.exe
2. A new window will pop-up as you can see below. On the left side are 3 main navigation buttons called New, Parameters and Mods. In the top right corner are some further menu items.
3. Alrighty, lets configure the tool first. in the top right corner click on the little gear and you'll go to the options menu. Basic settings should be as below but you still need to tell the launcher where to search for your mods. click on the little folder icon middle right and navigate once again to your main ARMA 3 root folder (don't select any mod folders, the toll will do that for you).
4.If you click left on MODS you should see all your mods in a list. to activate them you need to click on the little square in fron of a mod. you can also drag them in the right sequence which is important for correct functionality of our mods.
5. Once done, you can save the set-up by clicking on the right side on the little downwards facing arrow and than by clicking on 'save as'. From there you can also load mod set-ups.
6. On the bottom left you can also press on the little down-arrow to select a mod preset and directly jump into the game.
7. For all the more techy guys with their custom pc specific modlines, you can also define the same values in the launcher. Navigate to paramaters on the left side menu and change the values in both the basic and advanced tabs to your liking.