My wife Adrianna and I raised two boys and a girl during the 80s and 90s. Simon was the oldest, Jennie the middle child, and Seth was only a year younger than his sister. Being close in age, they got along well with each other and were generally well-behaved.
We used a variety of disciplinary techniques, depending upon their ages at the time. These included time outs, depriving of privileges (TV, friends over to visit, treats etc), and early bedtimes, which worked especially well if their misbehaviour was partly due to being overtired.