Each time you have to copy paste this, and pay attention to not forgot to change it in your UITableViewCell or make a mistake writing a wrong number.

titleLabel.text = "Title"
titleLabel.textColor = .black
titleLabel.font = .systemFont(ofSize: 34.0, weight: .regular)

detailLabel.text = "Detail description."
detailLabel.textColor = .black
detailLabel.font = .systemFont(ofSize: 14.0, weight: .semibold)

spacingConstraint.constant = 10.0

Total:

• 4 constraints
• 7 lines of code to duplicate

With Sejima

Each time you need this:

header.title = "Title"
header.detail = "Detail description."

UIAppearance

And to doesn’t make mistake, just once in a ThemeManager or what you want:

// Appearance for every MUHeader instance
MUHeader.appearance().titleColor = .black
MUHeader.appearance().titleFont = .systemFont(ofSize: 34.0, weight: .regular)
MUHeader.appearance().detailColor = .black
MUHeader.appearance().detailFont = .systemFont(ofSize: 14.0, weight: .semibold)
MUHeader.appearance().spacing = 10.0

// Appearance for a specific parent class
for vc in [UITableViewCell.self] {
    MUHeader.appearance(whenContainedInInstancesOf: [vc]).titleFont = .systemFont(ofSize: 14.0, weight: .light)
    MUHeader.appearance(whenContainedInInstancesOf: [vc]).detailFont = .systemFont(ofSize: 10.0, weight: .bold)
    MUHeader.appearance(whenContainedInInstancesOf: [vc]).spacing = 4.0
}

Total:

• 2 constraints
• 2 lines of code to duplicate
• 8 lines of code to be sure your header always look the same

One more thing

You can also design it directly in your .xib/.storyboard using @IBInspectable.