If your home needs a new porch, or a reconfiguration of the steps is required for comfort or safety, you can design a new approach to your home's entrance using an age-old builder engineering formula. Be sure to check with local building codes before starting a project like this: Most communities don't regulate smaller projects like this, but since steps are potential hazards, it's better to be safe and get permits if they are required than to have your project rejected after the fact.
Observe your home from a distance, such as from across the street, and gauge where the new steps would be most visually attractive for your front entrance. A porch staircase has value as a decorative feature, so don't overlook this potential.
Role play the many ways different visitors naturally approach your front door via the porch. Delivery people, mail carriers and other visitors choose a comfortable pathway from the street or driveway to the porch, and this pathway will usually be a direct "bee-line." Your step unit should align with these natural pathways to make its location convenient for everyone. Step units that are placed in strange, unnatural locations will be awkward and annoying.
Measure the height from the deck of the porch to the ground. This measurement is the amount of lift the step unit must somehow accomplish to transfer a person from the ground level to the porch level. Be precise with this measurement: it matters.
Measure the distance from the porch and away from the house that you can afford to use for the steps. This distance needs to be level and one elevation if possible. This measurement denotes allowable and potential run length of the staircase. You probably will not use all of this run length, but you need to be aware of the limits.
Calculate the width of the stair treads (the part of the step where you place your foot) and the high of the stair riser (the vertical part supporting the tread) so that, when added together, the product is 17 inches. This "magic rule of 17" will always result in a tread-and-riser combination that is safe, natural and comfortable for human beings. Any deviation in this calculation is unsafe and usually out of compliance for most building codes.
Experiment with various combinations of tread and risers and find the solution that results in enough lift to get from the ground to the porch within the allowable stair run distance. All steps in the run must be the same riser height; it is neither safe nor permissible to have partial or "shorted" steps in the run to make the steps fit the space.
Design sturdy banisters and hand rails on porch steps that are high in climates where ice and snow may accumulate on the steps or if you have a senior citizen or disabled person in the home. Banisters and hand rails should be on both sides of the steps.