I don't know about 'best', but my last run was totally clear/amber shatter w/o a vac.
I did a typical butane extraction into mason jars w/ a qp of trim. When the butane was mostly evaporated, but not thick, I slowly added 1/2 bottle of everclear (1bottle/half pound) to the mason jars. You should see a pretty dramatic interaction (bubbling). Let sit for about 1/2 hour (w/ just an occasional stir) till all bubbling stops. Now wait, and in about 1/2 hour the real interaction (winterization) will start (quite visible 'roiling'). place in freezer for 12 hours. After 12 hours, remove from freezer and strain off into individual glass containers w/ coffee filters, return to freezer while straining. To make shatter, you must do thin pours (thick pours = budder), so you only want about 2" of liquid in a pounder glass as each of these glasses will be an individual pour.
At this point, you should prepare your stovetop to evap the mixture. I used pots of water w/ pyrex dishes on top (kind of double boiler method). I had 2 setups going, if you stagger pours you can keep the operation flowing smoothly. I tried to keep the water below any real boil - just the bubbles that appear at the bottom of the pan. At this time, you also want to make sure your scraping setup is prepared. I laid out a piece of parchment paper w/ lots of clean razor blades.
Take out 1 of the glasses from freezer and remove filter (all the fats, etc will be visibe on filter). pour into pyrex dish on hot water. the mixture will go cloudy, then clear, then form beads of oil (about 15-30 min). After totally clear and beaded, take a blade and 'smush' down all of the beads and return to heat for 20 min to get any last trapped impurities. Once you figure out your timing, you can start a 2nd pyrex dish (on a 2nd pot of water) partway through the 1st 1 finishing.
Now it's time to collect your goodies. Using individual blades to collect the oil, scrape pyrex from one end to the other. When blade is loaded, place on parchment paper to cool. This process is much easier to do if you keep the pyrex on heat to make the product more pliable. After just a minute, you should be able to 'snap' the glass off of one blade w/ another to start your pile of absolute shatter. Be careful not to lift and relower the blade while scraping as this will cause visual imperfections.
This is what I did, but recommend anybody evaluate safety concerns/applicable laws for themselves. I had a return of 14 grams off of a qp of trim. There is a pic of the finished product in 'share that dab stash'. It's the one that looks kinda like hashbrowns due to the individual scrapes.