The Evangecube, or as I call it the “E-Cube” from E3 Resources has been my “go to” for International missions. When language is a barrier, even when using an interpreter the pictures help to reinforce the good news. The cube comes in three sizes. The largest size is good for teaching others how to use it or when presenting the gospel to large groups who may have a difficult time getting close. The regular size is great for all occasions and the one that I mostly use on missions. The smaller cube is great for strapping to a backpack using the carrrying case that E3 makes for it (sold seperately).
Im not going to go into great detail here on the instructions. I will instead include a link to the Evangecube insert on their resources page.
E3 also has cards with the same images as the E-Cube. They fold flat for easy packing. I usually carry one in my billfold because I always have it with me.