Phelan has an intuitive approach to art-making, working from imagination and memory to depict meaningful ideas or personal experiences. Recurring motifs anchor his compositions – text fragments, boxes, symbols, trains, clocks, churches, and simplified figures. His distinct drawings are often reminiscent of aerial maps or architectural floor plans. Currently, his work reflects a methodical process of mark-making, which accumulates over time to create directional swaths of color. He frequently rotates and covers both sides of the paper while working, causing the surface to become weathered and sometimes burnished.