Rub all leather INSIDE thoroly with mink oil
Wear your oldest, thickest socks - cotton preferred. They WILL take on oil and dye, so make sure they are a pair (or two) you are about to toss.
Start loosely tied. Tie a little tighter each hour, doing easy on-foot woork (more standing than walking.) When you have the boots tied down tightly, the next day will be for activity. That night, flex the toe of the boot up and down my hand, as that is the part that will "bite" your foot if not broken in carefully...
Gradually increase on-foot activity over the course of a week, and keep the boots well-oiled. Mink Oil will enhance the waterproofness (?) of the leather and will help it mould to your feet...
After two or three months you should be able to wear them without socks if necessary, and experience no discomfort.
DO NOT LET ANYONE ELSE WEAR YOUR BOOTS! EVER!
Key fitment areas to watch when you buy boots...
Ball of foot. Should be comfortable to _very_ slightly tight. NOT loose.
Heel - Should be comfortable, with NO room to move. NEVER tight.
Toe - should have adequate clearance for top of toe, and sides of toes. Pay especial attention to fitment around small toe - this can and will cause trouble later. Toes should NEVER be tight!
Arch - boot should feel like it comes right up to your foot. Arch should neither put pressure on the sole of the foot, nor should it have airspace between foot and insole.
Ankle - WHen tightly laced around ankle, boot lips should NEVER touch in front. A little air is good, more better. If the lips touch, you will not get proper ankle support from the boot.
A note on steel toes - I know men who have lost toes to steel caps! You are looking for more of a "cup" style toe than a cap. A proper safety toe now has a cap WITH a base plate (all one piece) that will extend beck to the front of the arch or so. A plain cap will cut thru the sole if the load is heavy enough, and you will have loose toes in your boot. A "cup" style toe (steel or composite) will protect your toes by keeping its integrity. In extreme cases, the entire cup could be pushed out the bottom of the boot, with the foot following. You will have thoroly wrecked your boots, but you will still have all your toes...
A few things to think about...
FFZ