Levels 1-10
Finish Deathknell before moving into Brill. Tirisfal's roads are forgiving, but its caves, ruined towers, and undead camps turn one long circuit into several separate Hardcore decisions.
Keep the Mills above ground
The Mills Overrun and Deaths in the Family can be staged from the outdoor road edge. The Family Crypt is a different commitment: do not let outdoor progress pull a solo character through the crypt entrance.
Split the Scarlet campaign
The western warrior tower and the eastern officer camps are separate trips. Repair, train, and reset in Brill between them; chain progression does not make a dense tower safe.
Where next
Continue to Silverpine Forest after level 10. Train, repair, and clear bags in Brill or Undercity before taking the southwest road.