What u need is to reduce the jitter to the least allowed for that stat attribute. There's a mod out there which ups it to 50% instead of usual 20% so if u r willing to spend eternity rolling for a good seed, u can theoretically get some stat upped +50%, same goes for lower range jitter too.
Also, not every stat/attribute on an item has same jitter range, e.g. look at a hallowed helm in vault, the +1 skill has NO jitter, the vitality res has a large jitter & health regen has only 2 available values, so u may want to move some or all values important to u into NO jitter array.