I avoided lace dresses for years because I assumed they all meant a slip underneath that bunched up round my hips by lunchtime, and a hemline that let too much daylight through in the wrong places. The ones that fixed that for me were lined properly, built in as part of the dress rather than a separate thing you have to buy and fight with, so the lace sits on top doing the pretty work and something sturdier does the actual covering.
A lace dress is easier to live with than it looks if you stop treating it as an occasion-only thing. Flat sandals and a denim jacket take it right down to ordinary. A plain cardigan in a colour pulled from the lace pattern looks deliberate rather than mismatched. Boots and tights make it work through the colder months, which surprised me the first time I tried it, because I'd filed lace away as a warm weather fabric only. The trick is treating the lace as the detail, not the whole outfit, and building around it with things that have no pattern at all.
Before buying, I check what the lining is made of, because that fabric is doing more of the work than the lace ever will. Polyester lining feels cheap against the skin and doesn't breathe, cotton lining is cooler but creases if you sit down for an hour, and a stretch jersey lining moves with you and forgives a big lunch. I also look closely at where the lace pattern falls, because a scalloped edge that lands mid thigh on the model photo can sit somewhere entirely different depending on your height, and a floral motif placed badly across the chest draws the eye exactly where you don't want it.
For fit, go by your usual dress size first, then check the armholes, because lace has very little give and a tight armhole will show under the arm every time you reach for something. If the dress has a defined waist, sit down in it before deciding, since some linings pull tight across the stomach when you bend. Watch the shoulders too, lace straps that look fine standing up can dig in once you've been wearing it a few hours, and that's not something you notice until you're halfway through a long day.
The detail that makes a good one worth having is a lining that stops a few millimetres short of the lace hem, so you get a soft edge of pattern with nothing visible behind it, rather than a hard cut line that gives the whole thing away as cheap.