Our church has just gone through a study of Ephesians, which was great. I thought I'd share just a couple of things I learned.
Read the letter start to finish in one sitting. As many times as you can. This gives you the whole writing in perspective, start to finish. (Actually, this works for any book of the Bible. It's just easier on the shorter ones).
When you do this, you may notice that Ephesians starts out very theological and theoretical. It's certainly hard for me to get my head around the mysteries Paul writes about in the first couple of chapters.
By the time we get to chapter five, things are getting very practical. Then, at the very end, Paul starts writing about powers, principalities, spiritual armor and prayer.
There is nothing more practical than prayer and the spiritual outworking of our faith. It's hard to imagine that the stuff we cannot see has the most direct impact on our lives, but it does. Without prayer, and the rest of God's spiritual armor, we are completely helpless. And, literally, defenseless.