Yes, Filling the Bowls is part of my Play also! I Fill a Lot of them! But My End is Mostly caused as a result of them too, LOL. On the Board below, I was able to Fill the Rurple Bowl and the resulting Cascade filled the Green Bowl too. 
The Board below is a result. The “Green Dagger” is not a problem, but the “Red Bomb” will be if I can’t "Explode it away from my “Corner”! 
I took out the 3 Greens above my “Green Dagger” and got a Cascade and the Board below! So Lucky, LOL! 
I am always on the lookout for “Challenge” completions also. I do not Dwell on them, they will come!
After taking out that Challenge, I got SUPER LUCKY with the Board below! 
My MAIN GOAL is ALWAYS Try to Protect my Corners! This Helped a Lot! 
Or so I thought. After that move, the Blue Bowl Filled and gave me the Board below! Oh Crap, the BLUE Attack continues!
I was Lucky to Start with this Board. It had DOUBLE Protection on the Corners. I was not unable move the “Blue Dagger” up. I had Won about 117M Coins before this “Blue Attack”. After the resulting Cascades from my Short Attempted Defence, I had Won 153M Coins. Thats your answer @Cathylee 
When the “Blue Attack” was over I had 36M more Coins, the Board below, and a Fresh Start. 
The attacks continued as you can see below!
I play the “Creepers” and the Center of the Board and the resulting Cascades are AMAZING! 
I eventually Lost a Corner, NOW I Play that Side for ALL it is Worth! I’ve Won about 189M to this point,
I got in a hurry and missed some moves in the End on this one trying to take Pics, LOL! I only made 7 moves! I Ended with a 202M Win. Those 7 moves got me 13M! I only went to look at the JoO Instructions but such a Great Board (Double Corner Protection) appeared, I could not pass it up, LOL Hope the Pics Help some.
I play to Protect/Defend my Corners. I am on the Lookout for Challenge items, but I do not dwell on them. I try to Fill the Bowls knowing they can Help me a Lot but can Hurt me too. In My End, I am looking for Super Cascades to Pay me Super Coins!