Also, don't shy away from less appealing cuts of meat. Some just need to be cooked at a lower temperature longer for the fibers to loosen and the fat to dissolve. For example, if you cooked beef stew meat on the grill it will come out tough. If you cook it under a lower heat over time (like in a slow cooker) the fibers and fat will have more time to break down to make the meat really tender.
Other than cooking at a low temperature, you can also tenderize the meat with a salt based rub or using vinegar. A chimichurri sauce with a lot of vinegar mixed in helps to tenderize meat very well if you let it marinate overnight and want to cut into cubes to grill on the grill.
