Purchase soil in a large enough amount to make a mound the size of your choosing. If you want to create several berms of varying sizes, you may want to get a truckload and move the soil around with a wheelbarrow to sculpt your landscape. Shape into an oval, circle or make it nonuniform.
For roses, build your berm in a very sunny location. Roses perform better in direct sun and need at least 5 or 6 hours of sunlight daily. Plant roses such as miniatures, hybrid teas, floribundas or moss and Damascus. Plant the tallest in the center and lower growers around the perimeter. Climbing roses may take over unless you add a trellis or arch to a large enough berm.
Add compost around plant bases. Just a handful or two around drip lines works fine. You can work it into the soil slightly or just leave it above ground.