Don't over commit on defense against the ball carrier. He can't run you over, so he must go around. If you charge straight in, it is very easy to juke you and score. But if you break down and keep your feet moving, at the very worst it will slow him down and at best you make the "tackle."
Some of the techniques and skills that one needs in football is the ability to hit and take a hit. The ability to tackle below the waist. Lastly the ability to catch or block when needed.
Flag football or touch football
In Australia, the game of "Touch" is played with a football. It is sometimes incorrectly called "Touch football", but it has no allegiance to the game of football.
Yes, some 3rd graders play tackle football. Many younger kids also play touch and flag football.
"touch rugby"
NRL is tackle football, there are kicks in play (start of field) and there are converisons. Touch football requires you to touch a player, no kicks during plays and no converisons.
In an on-sides kick the football does not have to touch the ground. The football must travel at least 10 yards before the kicking team can legally touch the football.
Touch/Flag Football.
There is no exact record of when touch football was developed, but the first official game was held in Australia in 1968. Touch football is a non-tackle way to enjoy playing football for both males and females.
John Kennedy and his family played a lot of touch football. I am not sure about the White House lawn part, but I know he played touch football while he was President.
Here in America touch football was invented the mid-nineteenth century with the first college game taking place in 1869. It was in the twentieth century that touch football gained in popularity.
Basketball is better than touch