Hello I'll tell you opposite to Goosegirl ,its the way I was taught by a groundsman and it works first apply a fertilizer like grow more encourage the grass to grow stronger ,then apply an appropriate lawn weed killer (wont suggest the best ingredients on here as the moderators get upset) apply exactly as the packaging says ,then after 5 days when the weeds are curling up give the grass a mow,I've never used a "weedand feed lawn fertilizer not enough of any ingredients in them ,when you've killed the weeds do the moss using Sulphate of iron at 4oz per gallon of water to 10 square yards of lawn it kills moss over night then scarify the lawn, then slitter/aerator /spike the lawn ,do not spike then scarify it doesnt do the scarifier tinescany good jezza