There is no way I could cover everything, but here are a few things
1. Know your personnel and play to your player's strength. Don't send guy like Anquan Boldin on a go route and expect it to work.
2. Have something like a gameplan. With the Browns I would be looking to get Richardson 20+ carries a game. Then keep track of that. What I do is think minimum of 5 carries a quarter. Then you may want to get your back up RB anywhere from 5 to 10 carries. Keep a running count in your head and this could help you have a balanced offense.
3. Plays are designed with a purpose. Some beat cover 3, some are designed to get only 5 yards or so. Learn those things and learn how to read defenses and you are well on your way. (to read defenses just go into practice mode and change the defense's play and notice the differences)
4. Don't always pass from 4 WR sets or always run from big sets. Mix it up.
This could be how series could unfold:
1st and 10 -- singleback slot, HB stretch
2nd and 7 -- singleback y trips, Stick
3rd and 1 -- singleback twin TE, HB power
1st and 10 -- singleback twin TE, spacing
2nd and 5 -- singleback y trips -- HB zone weak
3rd and 2 -- singleback normal, HB dive
1st and 10 -- singleback slot, Hb stretch
2nd and 8 -- singleback slot, SE under
3rd and 1 -- singleback twin TE, h-zone weak
1st and 10 -- singleback slot, PA Slot crosses
Then after a couple drives of this, attack the defense vertically. Don't try t get a big play every time, be patient and think of the whole game.
On defense try to match personnel unless you think they are trying to deceive you e.g. If you are the vikings you can line up in 4 wide all game but I am not going into my dime defense. Also pay attention to matchups and call plays that correspond well.
tl;dr -- Go into practice mode and run plays from your playbook against different defenses. In game know your team and your opponents strengths and weaknesses