The easiest way to make a beginner quilt pattern is to stick with squares and rectangles to avoid cutting or sewing on a bias or diagonally. Select the background fabric, then cut out squares of complementary colors and prints. Arrange them on a flat surface until an eye-pleasing pattern emerges.
The background fabric is the piece that ties the entire quilt together. The squares, or rectangles, may be of any size but, at least for beginners, larger is better. For example, if you are creating a baby quilt, 36 6-inch squares would be enough to make a suitably sized piece. A quilt for a double bed may need four times the number of squares if you kept them the same size. Larger squares make the quilt less complicated.
Arranging all the squares before starting to sew makes sense. Perhaps you have a background fabric that is black with yellow polka dots. You've also cut out squares from the same material, as well as florals and other patterns that have bits of black and yellow in the design. Laying out the squares helps you decide which squares complement each other, side by side, as well as how they look against the background fabric.
Using squares and rectangles also means you don't have to create patterns for the pieces. If you were making a quilt with butterflies or birds, you'd need to make a pattern, trace it onto each fabric piece and then cut. Then you'd need a background square cut for each piece. For squares and rectangles, you just need a measured cutting board to keep the pieces uniform.