So, say you're that missionary wannabe I described in Missionary Material 3. What do you need to do to become a missionary?
Well, even though you might need to hear it, I'm not going to share the nuts and bolts of what probably needs to happen. (But if you really want to know, leave me a comment and I'll be glad to get into that with you.) I'd rather focus on the preparation of you as a person--developing the "material" that will make you an effective missionary.
Now, if you remember from what I wrote in Missionary Material 2, your walk with Christ and your spiritual character are WAY more important than whatever strategy or approach you use. So, even if you might be excited about what I wrote in Missionary Material 4 regarding business and all that--don't get too excited just yet. You need to be discipled, first.
Have you been discipled? Have you ever hung out with a deeply spiritual and Christlike person whose mind was on how he/she could please Christ and serve him? Have you allowed this person to peer into your life, counsel you and coach you? Have you allowed them to suggest to you how you need to change or where you need to grow? Have you spent time in prayer with them? Have you spent time serving alongside of this person in real-life ministry situations? Have you joined this person when he/she has spent time with those outside the faith?
If you have answered "no" to any of these questions, I think you need to find someone like this, first, and ask them to disciple you. Live with them if you can. But whatever you do, don't get someone who is a good talker (can explain anything about God) but never seems to get around to doing any ministry or spending time with anyone outside of the Christian community. If you allow yourself to be discipled by someone like that then you will probably become like that, too.
Allow yourself discipleship time to change into the kind of person God wants you to be. This is primary before any kind of ministry--cross-cultural or not. Of course, you will always be growing and discipleship is ongoing--it will never end. But that doesn't mean you shouldn't take time to be discipled, first, before jumping into a situation where you will be tried in ways you've never even imagined before. You need time to deal with the issues deep in your heart. You need time to allow others to help you grow strong where you are weak.
Nobody runs a marathon without first having gone through extensive personal training. It doesn't matter how much academic knowledge you have about running. Nor does it matter how much you have spent on your fancy shoes. You better be in shape when the whistle blows.