This trophy will take a while to obtain as this game can get incredibly frantic from Day 45 onwards, the reliance on power ups greatly increases at this stage and it can cost tons of coins because of this.
If you have the unlimited energy purchased (which costs real money) then this could really speed things up but it's more fun to play this game in short bursts anyway.
If you choose to go without the unlimited energy and would rather wait for the coffee cups to recharge, the game will only give you up to 3 coffee cups (which take 30 mins real time each to recharge).
You can get more than 3 if you purchase additional ones from the game shop using your coins. Usually if you complete one of the endless days (10, 20, 30, 40, 50, 60) for the first time then the boss will give you a coffee cup as a reward.
The game requires you to pass more and more levels to pass the day as the days go by. You could be doing as much as 4 stages per day by the last 10 days.
If like me you don't want to dish any money on this game, grinding coins on easier stages can help greatly in the long run.
Before you dish out money on power ups, you might want to purchase the upgrade which means you get 3 power up slots instead of 2. It costs 40,000 coins but it's so worth it.
You'll also want to purchase the 1.2x score multiplier if you intend on getting the 170 stars in this game. It's expensive but it makes 3 starring days so much easier.
EDIT: You can buy a 1.4x multiplier for 140,000 coins after purchasing the 1.2x. I'd recommend buying this because it was the only reason I passed Day 59, the score required to pass is high on this day and it's hard to score because you're struggling not to fail.
The best stage I have found to grind coins is Day 10 because it's an endless stage and can go on as long as you can keep up. It's important you don't use your power ups while grinding coins, otherwise you'll be wasting your time.
I can get about 5,000-6,000 coins added to my bank just by playing this level for about 3 minutes. I usually score around 10,000-15,000 points.
The reason this level is good because there are only items on the belt and it gives you power ups regularly enough. There are no bombs, babies or dogs on this stage which is the sort of stage you want to grind coins on.
EDIT: Another good day to attempt is Day 43 because it's 3 missions for scanning a lot of items and there are no dogs or babies. The 2nd mission on this day is annoying because the scanner fails to scan the items a lot but just be prepared to put items through more than once and you'll be fine. My personal best on this day is 45,000 coins and that was for a 68 combo on the first mission.
The best power ups I found to use if you just want to pass the later stages are
Super Discount (2,000 coins) - Yes you have to enter a code for the items but the useful part is it will clear the belt no matter what is on it. So for this reason, it's better than using Clean Up AND it will give you a nice coin boost since you knock off 7 items at once. If you'd rather use Clean Up then that is your personal choice.
EDIT: I'd recommend Clean Up on the later days because the belt moves so fast on some levels that the super discount could make you fail. Clean Up is not all bad, it collects any coins on screen at the time and gives you points for the items on the belt, but it won't spawn the coins from the cleaned items.
Laser Scanner (3,000 coins) - Not so useful on the faster stages because the scanner is not as fast as it seems, however this item is very useful for getting 3 stars as it helps you build a high combo. Use during the beginning of the harder stages if you are not hitting the required score to pass.
Speed Down (1,000 coins) - This is a cheap power up and it helps a ton on the later stages, try and accumulate as many as you can. It only slows you down for 10 seconds but that is plenty of time to clear the belt hopefully.
EDIT: You can use as many of these Speed Downs as you want at a time and they slow the belt down one level for each one used, these saved me on Days 55-60.
Chance (3,000 coins) - This is an expensive power up and you could burn through these quickly if you're not careful. Before you use these, you should consider how to better use your other power ups because these should only be used if you unfairly failed a level in my opinion.
EDIT: It's recommended that you have about 20-30 of these on you at a time when attempting Days 55-60 as you will get some cheap fails on these days
You could also spend your coins on coffee cups if you have plenty of coins.
Best of luck getting this, this might be your joint last trophy on this game but you get unlimited tries at passing days if you're willing to wait for the coffee cups to respawn.
On an unrelated note, the tile for this trophy is Silver yet this is a Gold trophy, I'm glad this is a Gold trophy and not Silver because this was a bugger to get!