My personal tip is related to one in the article: Instead of a full spectrum LED, use a near-infrared (Eg 850nm) light and shine it on your forehead for 5-10 minutes. The concentration gains I get from this are substantial, and they last up to 2 days. Security camera IR lights with 850nm can be had for $30 or so at Amazon. The name of the mechanism by which this works is called photobiomodulation, and there’s thousands of papers on how it improves body function.