Add lacto and yeast at a 3:1 ratio to start. To start for a batch I'll make a starter that is half dextrose and half malt extract to about 1.025 - 1.030 or so. You can go higher if you would like, 1.030-35 is fine also. I'll then put on my stirplate overnight (16h or so) at 98F .
Decant and add a small amount of starter (malt extract only this time) and let it go for a bit on the stir plate at room temp before you pitch. This way you'l have plenty of lacto AND they will be ready for beer. I pitch the entire starter into warm wort (@98 degrees) and let it naturally cool down overnight to 65-68 degree range before pitching a vial German Ale yeast. (no starter)