It is tempting to overemphasize the role of sophisticated equipment and fancy set-ups in modern chemistry. This is why I am encouraged when people do more with less. Of particular significance are colorimetric tests that do not involve any dyes that undergo insane conformational changes to reveal what is happening at the molecular level. Below is a simple reaction I came across while looking for examples of boron/amide interaction (something that is of interest to our lab at the moment). This is Matteson’s old work and the best part of the experimental section is the description of how the starting boronic acid was stripped off the boric acid impurity. The authors state that “… was freed from boric acid by treatment with 50 mL of methanol and distillation until the distillate showed no green boron color in the flame when ignited.” We need our students to never forget that trivial tests such as this simplify life and make practitioners of synthesis look resourceful when they present research findings at conferences or job interviews. The irony is that this can look more impressive than the seemingly more elaborate modern techniques. Let me know if you are aware of additional examples where deep insights about chemical matter are made using everyday tools.
amphoteros 
Sophisticated methods make a better job interview story… Last year, I was working on inorganic chemistry project that involved solid-to-solid transformation of cesium salt to sodium salt of unstable anionic complex that decomposes readily in solution. I found the way to do it without decomposition, in a slurry form, where the starting material gradually goes in and the product precipitates at the same time. We did not have spectroscopic methods in house to follow the transformation, and Cs assay done by analytical service provider was really expensive, plus had a two week turnaround – this really limited how many samples I could submit when trying to optimize the exchange. So I resorted to using a magnifying glass – the particles of Cs salt were cinnamon red-brown, the sodium salt was coffee brown-black, the Cs-scavenger byproduct was bright white. All I needed to determine endpoint was to watch the red-brown particles disappearing from the slurry, and then give it extra few hours just to be sure.
This is classic. Love it.