Make a Design Mock-up
Make a mock up of your project to confirm the combination of design elements and their placement. Use masking tape to simulate chair rail and decorative frames and to tape up a strip of wall paper border for effect. Purchase sufficient rolls of wallpaper and border, along with the wooden stock for the chair rail and frame trim.

Record Measurements and Positions of Mock Elements
Record measurements and positions for the mock elements to duplicate in the actual installation.

Mark the Layout on the Walls
Mark the positions on the wall with horizontal and vertical pencil lines, using a bar level to ensure they are either level or plumb, as appropriate.

Remove the Mock-up
Remove the mock-up, once the measurements and pencil layout are complete.

Add Paste Activator to the Pre-pasted Wallpaper Border
Apply a paste activator to a pre-pasted border to ensure a good bond on the wall. A small paint roller and paint tray make application easy while working on a temporary plywood workbench.

Book the Wall Paper Border Strips
Book the wallpaper by folding the pasted sides together for a few minutes prior to putting them on the wall. Booking ensures that the adhesive is thoroughly moistened and ready to apply.

Apply the Borders
Unfold the "book" and position the border beneath the appropriate pencil mark from your earlier design layout. If your wall paper pattern as a one-way design, be sure to position it with the correct side upward and be consistent.

Position the Border and Remove Air Bubbles and Wrinkles
Press the border strip in place, removing air bubbles and wrinkles with a wallpaper squeegee.

Trim the Ends with a Utility Knife
Trim the ends with a very sharp utility knife where they butt against doorway trim, running the knife along a wide putty knife as a straight edge.

Pre-paint or Pre-Stain the Molding
Pre-paint or pre-stain all the wooden molding before you make any cuts. It will save time, tedious work, and lots of drop-cloth and paint mess inside your home. Set up your painting area outside, laying the molding across saw horses to make a convenient elevation that does not required that you bend.

Prepare a Work Area for Cutting the Molding
Prepare an outdoor work area for a miter saw using plywood and saw horses. Assemble your remaining tools. Include safety glasses because you will be using power tools.

Set Up a Base to Hold the Molding at the Correct Elevation
Set up a length of rigid stock lumber to make a temporary base/support system for the lengths of wooden molding and to facilitate cutting them to identical lengths. This base must be perfectly perpendicular to the saw blade and hold the molding that you are cutting at the same elevation as the bed of the miter saw. It will serve the same purpose as a fence on a table saw.

Mark the Required Length on the Base
Measure from the saw blade and mark the required length for a series of molding cuts on the stock base.

Clamp a Stop Block in Position on the Base
Clamp a stop block on the outside of the mark. Be sure to allow for mitered ends on the molding as you measure and mark.

Miter the Molding and Cut It to Length
Miter the ends of the molding as required and cut the required lengths. When you cut the molding to length, butt it against the stop block and then cut--each piece will be of identical length until you reposition the stop block.

Mark the Wall Studs Along the Horizontal Pencil Lines
Use an electronic stud finder and pencil to mark all the studs along the horizontal pencil lines for the chair rails and members of the decorative framing.

Secure the Horizontal Molding with a Pneumatic Nail Gun
Secure the horizontal pieces on the wall, using a pneumatic nail gun to drive the nails through the molding and into the studs. The nail gun is fast and eliminates the likelihood of dents from misplaced hammer blows.

Glue the Vertical Molding with Construction Adhesive
Apply small dollops of construction adhesive every few inches along the back of the vertical members of the decorative framing to glue them in position on the wall. There were no studs in the wall where we needed to attach them for this project. We will still drive in nails at opposing angles to each other for additional support, but it is the glue that binds them to the wall.

Measure for a Frame Above the Fireplace
Measure for a frame above the fireplace surround.

Add the Molding and Plinth Blocks
Add molding and plinth blocks to the corners of the frame at the ceiling and immediately above the fireplace brick. Plinth blocks are attractive and also eliminate the need to miter the corners.

Fill the Nail Holes
Fill the nail holes with spackling compound, applying it with your fingertips. Touch up the holes with paint. If you stained, use wood putty in the correct color.

Add Wallpaper to the Area Inside the Frames
Add wall paper inside the frames beneath the chair rail, if desired. Cut the overhang with a straightedge and utility knife and use a squeegee to remove air bubbles and wrinkles. In addition to ensuring that a wall paper with a one-way pattern is facing upwards and consistent with the border installed earlier, you will need to match the pattern on each piece so that the design elements are aligned at the same elevation across each strip all the way around the room.