If you're a TH7, or TH8 with L2 dragons (and not a hogger or GoWiPer) you are in our Little Dragon Crew.
AIMS: Your goal is to target 3-star attacks on TH7s and low TH8s (with L5 or lower ADs). If the Little Dragon Crew fails to three star any of these bases, someone higher will have to clean it up, so go all out for three stars. There's no value in going for a safe two-star.
SUCCESS: Aim to be getting a 3-star attack in on TH7s with nearly every attempt, and aim to be getting 3-star attacks in on weak TH8s around 50% of the time. If you're falling significantly below that, ask for advice. Once you are reliably three starring low TH8s you're ready to upgrade to TH8.
APPROACH: Typically mass dragon will be your approach, with three lightning spells to take out an air defence. Dragons should be deployed to attack the remaining air defence(s) as early as possible so as to avoid taking too much damage from them. Maxed Clan Castle Balloons or Hogs can help with this as they target defences, but take care not to feed them to the enemy clan castle troops. A max dragon is also an option.
WHEN: Attack as early as possible. This helps others plan their attacks as higher players need to know whether they will need to do any cleanups. Try to get your first attack in within the first hour or two of war, and the second as soon after that as real-life and troop training times allows. If at all possible avoid leaving attacks until the last 12 hours of war.
CLEANUP: If all viable bases are 3-starred before you have used both your attacks seek guidance on what to hit. There may be possible useful stars available higher up (for instance 1 star on a badly designed TH10, or 2 stars on a TH9), or there may be helpful scouting attacks you can do on higher level bases that haven't been attacked yet. In the event that there is nothing meaningful you can achieve, practice on a three-starred low TH8 base and try to attack earlier next time.
RESOURCES: Check out the TH7 Mass Dragon guide page.