Build a rectangular frame for the foundation of the post by nailing together pieces of straight lumber in a square at least six inches larger than the post itself. The frame should be at least six inches deep.
Pour concrete into the frame and stop when the concrete is about halfway to the top of the frame.
Insert a steel L-shaped pole into the middle of the concrete base. One side of the L-shaped pole should be fully embedded in the concrete, while the other should be pointing straight into the air at a 90-degree angle to the concrete base. This pole will reinforce the shape of the post and make it more sturdy.
Level the concrete by scraping a flat board over the surface of the stoop until it is even. Remove the wooden frame the next day if it will come apart easily--otherwise, wait until the cement has hardened for four days, and remove the frame. Wait for the cement to cure completely before moving on to the next step.
Remove the rectangular frame once the concrete has set. Wait for the concrete to cure before continuing to the next steps.
Lay the first course of bricks centered in the foundation. Leave a 1/2-inch gap between each brick. The more bricks you use per course, the larger your post will be. If you're not sure how large you want the post to be or what layout you prefer, experiment with the bricks and decide. The bar you placed in the center of the foundation should be pointing upward in the middle of the post. Once you've decided which format you like, pick up each brick one at a time and spread mortar on the sides of the brick with a trowel. Replace each brick on the foundation. The mortar should fill in the gaps between the bricks.
Spread the top of the first course of bricks with mortar.
Lay down the next course of bricks, spreading the mortar over the sides of each brick when you lay it down. Continue this way and build up the brick. Build up approximately five courses. As you build up each course of bricks, place a level against the sides of the post to ensure that the bricks are even.
Pour the concrete into the space in the center of the post, between the bricks. This concrete, plus the bar in the center, will reinforce the structure of the post.
Continue to build up more courses of bricks. Every five courses, stop to mix more concrete and pour more concrete into the center of the post.
Stop building the post when it's as tall as you want it to be. Wait for it to cure according to the manufacturer's instructions. Purchase a flat, square stone to place at the top as a cap. Mortar the bottom of the stone and place it on top of the post.