How do I secure a tarp on a roof?

According to homedepot.com, here’s the best and safest way to secure a tarp on a roof:

Assess the Damage

Avoid tarping a roof during a storm.
Wear appropriate safety equipment.
Use a ladder to reach the roof. Closely examine the area for broken shingles and other areas of damage.
Homeowners with a steep or slippery roof should assess the damage from the safety of their ladder. Do not step directly onto the roof.
Carefully clean the debris from your roof using your broom.
For safety and support, have a friend nearby to help you.

Use a measuring tool to calculate the surface area of the damage.

Choose a heavy-duty tarp in the appropriate size.
When unrolled, the tarp must cover the damaged area plus four feet of overhang from the roof’s peak.

The easiest way to temporarily secure a tarp is to use sandbags to weigh it down and keep it from blowing away.

For a more secure and longer-lasting fix, create an anchor board by rolling a 2 x 4-inch board into the tarp's peak end. Nail the tarp to the board. The board must be 2 feet longer than the tarp's width and sit against the roof to avoid collecting rainwater, snow, or debris. Screw the board to the roof as a temporary anchor using nails long enough to screw through the tarp, board, shingles, and decking.
Sandwich the tarp by nailing a second 2 x 4-inch board over the first.
Repeat the first two steps three times for the tarp’s remaining peak ends.
This is a two-person job!
Never stand or step on your tarp as it may be slippery.

Use your screw gun to screw through the four tarp-rolled boards. Use screws long enough to get through the various layers of material, ensuring the tarp is fastened securely. This damages the shingles so you’ll need to replace them when you remove the tarp. Luckily, replacing shingles is less expensive than the water damage that can occur if your roof leaks.
Secure the tarp’s remaining sides with additional 2 x 4-inch boards using a screw gun and screws. These boards do not need to be rolled in the tarp.