Whenever you prune a Tree improving its health should be your primary concern. This is also true when you need to prune trees that are within your property or near streets or walkways.
When planting your garden you should understand how your trees will grow over their lifetime that way you can provide enough room that natural growth can occur.
With established trees you must understand that simply pruning access towards the bottom of the tree may not be the right cure. You must always take into account the roots of the tree if you are pruning to provide access under them.
If you are widening a driveway, extending your patio or planing to allow heavy traffic over the roots of an established tree by pruning the lower branches you may find that in just a few years the whole tree will need to be removed due to root damage.
If you are designing your property for light duty traffic then the method of pruning called raising the crown may allow you to save a tree rather then remove it.
Raising the crown of the tree should be performed on well established trees.
With care you should first prune the tree for its health by removing any dead or unhealthy branches.
Once you have cleaned up the tree you can begin pruning the lower 1/3rd of the tree to raise the crown or branch area to provide access.
Only the first third of the tree should be pruned.
Proper techniques for removing branches especially the lower branches must be followed.
Remove most of the weight of the branch first and leaving 2 foot or more where the branch connects to the trunk of the tree. This will allow you to make the final cut without risk of damaging the bark or causing a tare out.
After removing such a large section of your tree you should keep close watch on it for the next few years.
There is debate as to whether sealing cut branches with prepared products will allow the tree to mend in the same way we would use a bandaid. Common practice in the last few years is to not seal the wounds but you should ask a local arborist for advice based on your specific tree and locality.