Tire replacement

Assuming you have a spare, what provision do you have for jacking up the trailer?
I was doing my car and realized most trailer frames have no real provisions for a jack. While at the tire center, a boat trailer was brought in with a flat. It appears to be even worse as the outer frame edge is elevated.
What type(s) of jacks do you carry, about what weight max.
Do you use the axle or the outer frame edge or a cross support as the anchor point?
Have you added anything eg a plate or a bracket to the frame that the jack will grab on or stay centered or not sliding while jacking? Have you modified the jack top to fit your frame eg a U-shaped fitting to grab the frame.
Does it matter if the framing is tubular (square or rectangular), L-shaped, or C-channel or a mixture?
Another question, do you unhitch the trailer, then jack up the frame? Do you leave the tongue up or on its tongue jack or let is rest on the ground. Do you attempt to keep the trailer level when jacked?
I was doing my car and realized most trailer frames have no real provisions for a jack. While at the tire center, a boat trailer was brought in with a flat. It appears to be even worse as the outer frame edge is elevated.
What type(s) of jacks do you carry, about what weight max.
Do you use the axle or the outer frame edge or a cross support as the anchor point?
Have you added anything eg a plate or a bracket to the frame that the jack will grab on or stay centered or not sliding while jacking? Have you modified the jack top to fit your frame eg a U-shaped fitting to grab the frame.
Does it matter if the framing is tubular (square or rectangular), L-shaped, or C-channel or a mixture?
Another question, do you unhitch the trailer, then jack up the frame? Do you leave the tongue up or on its tongue jack or let is rest on the ground. Do you attempt to keep the trailer level when jacked?