Well, first, only do it where you are comfortable and the facts/circumstances support.
In VA, it's required in restaurants due to the restaurant ban.
In OH, it's required due to the car ban.
In these two circumstances, you have no choice, and can modestly tell people who ask, "Hey, i'm just following the law, openc arry is required."
To get over nervousness, start off by open carrying where you are most comfortable - your neighborhood grocery store, 7-11, favorite restaurant, to from your house to your mailbox, etc. I usually carry an object in my carry hand - car keys, coffee cup, etc - just makes seem more normal to give that hand somthing to do, and in the back of my mind, I feel that if anyone ever lied and said I touched my grip in a threatening manner, I will be able to testify that this is not possible as I was holding a ___ in my carry hand the entire time as any surveillance tape or witness will attest to.