#6. Don't Crowd the Grill
One of the most prevalent mistakes home cooks make when grilling is adding too many items to the grill and expecting good results. Tip #3 talks about about creating grill grill zones for direct and indirect cooking but if you overcrowd the grill from the start, there's no room for 2 zones.
If you add too much to the grill and have a flare up, there's no place to move the food to. And let's face it, if you are cooking a foods that start dripping fatty juices, you are going to have flare ups.
No way around this so you want to make sure you have a cooler part of the grill to move these foods over to.
Another reason to not overcrowd the grill is similar to not overcrowding a fry pan when cooking inside. The more you add to the grill, the more heat your remove from the grates. If you remove too much heat, the meats will steam rather develop the desired grill marks and the end results will be terrible.
If you don't have a big enough grill for a large group, cook in stages or borrow a neighbors grill but be prepared to stay very busy at the grill.