I’m done with 21 skills and so far I have been trying to keep the tree Golden as in the first picture, but to no avail as you see in the second. As I get certain skills gold by reviewing, soon enough their “strength” expires and they become green or red. However the frustrating part is that when doing the practice session not always some skill turns golden. It is very de-motivating when that happens.

So the question is do I keep learning new lessons or do I review first and have everything golden before going on to new lessons.

I went on to Duolingo forums and the internet at large (here, here and here) and the general consensus is that if you review more often and keep the tree golden you will know the material better. However racing through the tree is more addicting and motivating.

I have decided from now on to focus on racing the tree – meaning give priority to learning new lessons than reviewing. Here are reasons:

• At Coffee Break Spanish I’m at an episode that starts to cover past tenses. In Duolingo I’m still ways away until I reach that lesson. I would prefer to reach them at the same time in different materials so that the concepts settle in better after attacking them from different sources. 
• Duolingo is not my only Spanish learning material, so learning every single detail from it is not that important.
• Memrise is much more efficient for acquiring vocabulary in long term memory (the app is faster, you can learn each word individually (instead of typing a whole sentence))
• and finally! I found a Memrise course with Duolingo vocabulary. 

So my strategy going forward is going to be keep going forward in Duolingo tree and only review when the average strength drops below full bars and also be at the same place in the corresponding Memrise Duolingo vocab course (though will need to do catching up!)

Here are the numbers for Day 12. Total was 41 minutes. Here is the breakdown:
9 Duolingo
20 Coffee Break Spanish episodes 52
12 Memrise

Till tomorrow!