lopping shears don't cut it
We have two pairs of lopping shears, both of which have the same problem. (brands: Corona and Fiskars) They seem sharp, but they are not cutting the last remnant of the branch, resulting in a very ragged cut of the last bit of wood.
I think the blade is not making intimate contact with the blunt "base." This is probably due to the fact that we abuse the shears, trying to cut branches that are too big, and then twisting around to make the cut.
What can we do with the shears to fix them, and/or to prevent this from happening again? Is this characteristic of less-expensive brands, or is it our poor technique? OR, is my analysis (they seem sharp) probably inaccurate?