Once you start noticing a receding hairline at the earliest stage, get castor oil and rosemary oil. Mix 15 drops of castor oil with 1 drop of rosemary oil in your palm, then massage it into your scalp consistently. It will save you from breaking the bank trying to restore your hairline later.
I've restored my hairline twice. My dad was already bald at an age younger than I am now, yet my hair is full and my hairline is sharp.
For a proper scalp massage tutorial, search for Austin Goh's scalp massage video on YouTube.
You're welcome.