dont open the grill constantly. when you smoke you should leave it closed unless you're mopping the meat or something else that needs to be done. in other words no peeking! every time you open it you release heat and it slows the cooking process even more.
also use your hand as a guide to the doneness of steaks. how this works is you touch the tip of a finger to the tip of your thumb and then press on the ball of muscle below your thumb and this will give you an idea how cooked a steak is. touch your index finger to your thumb, pretty rare, touch your middle finger to your thumb, medium rare. you can use your ring finger and pinky the same way but i consider anything above medium rare overcooked so i dont bother cooking past medium rare. this is but a guide but works pretty well. i dont like poking my meat with a thermometer to take a temp because as soon as you pull it back out your steak spits out delicious juices that would normally be on your plate instead.
do NOT stab steaks or any meat with a fork to flip them, use tongs. every time you stab the meat you release those tasty juices and you end up with a dry or drier piece of meat and that's not good eats. do not press on burgers, for the same reason you dont stab your steak. unless you like dried out meat. smashing a burger only forces out the juices it does not make it cook faster. if your burgers turn into meatballs on the grill consider putting a dent in the middle of each burger when you make the patties, that way when it pulls inward the dent will only flatten out whereas the flat burger will round out and turn into a ball. also dont overwork the meat as that will also cause them to turn into balls.
know how hot the grill is BEFORE you start cooking so you can avoid scorching your food or waiting forever for it to cook. hold your hand over the grate and count 1 mississippi, 2 mississippi, etc. if you cant get past 1 without screaming or pulling your hand away its too hot anything past 3 is too cold. 1-2 is for searing, 2-3 is for grilling and 3-4 is to keep almost fully cooked food warm until everything else is done. so press the meat with a finger, dont stab it or cut it open to see if it's done.
notice i said almost fully cooked, dont fully cook it and then leave it on the grill you'll overcook it and dry it out. the idea is to cook everything to whatever desired doneness at the same time so you can serve it all at once and all of it be nice and hot. hot dogs will cook much faster than a 1" thick steak so put the dogs on last and the burgers on after the chicken for example. anything with a bone will automatically take longer to cook than meat without a bone so all bone in meat goes on first. also do not overcrowd the grill, leave space between everything to let the heat go around so it will cook a little faster.
if you like putting bbq sauce on your meat as it cooks wait until it's kinda close to done THEN start saucing, dont sauce them as as soon as they go on the grill or you'll just burn the sauce and that isnt good eats either. you want to caramelize the sauce and give it a grilled taste, not a burnt taste. the higher the sugar content the easier the sauce will burn so remember that when brushing it on. consider moving the food to a warm zone away from the hot zone to reduce the chance of burning.
when serving steaks let them rest a few minutes after removing them from the grill. the reason for this is to let the juices redistribute into the meat. when you cook the steak proteins tighten up and this forces out liquid so when you cut into a steak fresh off the grill it spills its guts onto the plate and the meat will dry out. give them 5-10 minutes covered with foil before serving. this applies to other meat too.
grilling and smoking is awful good fun and can produce excellent food but it is wrought with way too many ways for it to go all wrong and leave you with a bad taste in your mouth. the problem is it's easy to cook on a grill or in a smoker but it's easier to do it wrong. grills are also like babies and the ocean, never turn your back to one or you'll regret it. smokers you can reasonably walk away from but not for long periods so stay close.
and most importantly have a fire extinguisher and a phone within reach should the extinguisher fail you. a water hose will work but not for a grease fire, it will only make it worse. everything but the fire extinguisher and phone are guidelines, not hard and fast rules. the extinguisher and phone are mandatory, not open for debate.