As was discussed in the Forrest expedition section the Confederates made little effort to prepare for a second day of battle. Many units retreated to the Union camps to find food and use the tents. Some units slept in line of battle where they ended the first day. Polk gathered some of his corps and retreated to their camp of the previous night well south of the battlefield. Beauregard shared a tent with Bragg so they probably discussed some ideas for the next day but there was no command council held to share information and plans. This disorganization does not allow Beauregard to effectively deal with the Union advance early on April 7.
The simple solution would have been to gather his commanders that night to discuss plans for the next day. The council of war would have been able to make a few easy decisions that would have changed the start of the second day of battle. The first would have been to arrange troops logically within the battlefield, not having some up front, some in the Union camps and some miles to the rear. Forrest might have been able to present his information about the arrival of Buell's army at such a meeting. A decision about whether to retreat or do something else could have been made.
Ignoring the possibility of a second day was a critical decision and a mistake. This is very similar to Grant thinking that the Confederates would not venture out of Corinth to attack him.