To teach students to think like scientists, the authors modified their laboratory course to include regular opportunities for student practice of inquiry and the scientific process. Their techniques are simple; they can be implemented without rewriting lab manuals, require little additional grading beyond typical lab reports, and are applicable across the science curriculum. Here, they provide four simple ways to emphasize questioning as a critical part of the scientific process. Pre- and post-lab questions are particularly easy to implement, requiring no modification of written lab manuals, no change to supplies or equipment, and no class time. They provide students with weekly practice in critical thinking and experimental design, opportunities for instructor feedback without a large increase in grading, and increased engagement in the lab activity. Mini experiments allow students to genuinely investigate questions without changing lab logistics or requiring large amounts of lab time. An independent experiment requires a full lab session and more preparation by the instructor but provides students with the invaluable experience of asking and answering their own scientific question--i.e., doing science.