Hey there! I was on the same boat as you days ago; I just finished the Box Challenge and I did not follow the 50% rule on the lesson 1 and also I did not follow it during the box challenge.

When I submitted my box challenge for official revision the mentor rapidly knew that I was rushing the course, and not following the times that brain needs to start adapting to the drawabox mindset.

So first of all, the 50% Rule is a must for what I can tell you, not only protects you to burnout, it also allows you to have fun as you mentioned before, because let's be honest, drawabox is great, but it isn't the most funny stuff on the world, it acts like a bridge to helps us develop the skills needed to have fun drawing, with that said, first you need to start that bridge and then face the reality that it's better to take some rests inbetween, otherwise you will end up being a professional bridge maker, but there will be no plan after that, you wont know what art attracts you, or what you can actually do with the skills you learned already or just you will forget the most important thing, that is having fun, and with having fun I'm not saying that drawing isn't something serious, but if you enjoy working you will always work with more passion and energy, and I honestly think that drawing follows that premise more than any other job.

Well, after that wall of text I'll tell you what I did, I guess that it follows very personal tastes, but maybe you find the joy of that rule with some of my ideas:

• Start a Sketchbook and draw everything in your desk. First drawing it flat, then trying to apply some shadow so it feels more real and then trying my best drawing contour lines to make it seem cool

• I'm also a Photographer, so maybe here we have something in common; I like to go out with my cam and take a picture of whatever I want to draw, it's a totally different approach to handle a cam wanting to take a pic of something I want to draw compared to take a photo of something you want to show as a photographer, both things work, but I noticed that if I go out with my cam thinking on the drawing my imagination goes more wild taking pictures of some stupid stuff like patterns on a rock or from some cool wood patterns on a tree instead of taking a pic of a complete forest and stuff like that

• Continuing with the Photography I have some knowledge of Photoshop and since I also want to practise digital painting I'm also learning Digital Painting from CTRL+PAINT.com he has a HUGE step by step guide to learn digital painting and its 100% free; he also has paid courses, but the biggest stuff is on the free side