This might be a silly question as I've been into photography for over 40 years, but here goes.
I've never been able to adequately master the technique of changing lenses in the field. Frequently I'm in a muddy or wet area so there's no opportunity to set one on the ground. Having to deal with back caps, a 70-200 in one hand and a 17-40 in the other is quite awkward. What are your recommended steps for changing a lens on a tripod in the field?