5 Frog Coins
To collect the 5 Frog coins, you must get 4 in the waterfall section and 1 as a bonus for collecting at least 60 coins in the 2 sections.
Collecting 60 coins is optimal because you will skip a text box that appears if you collect more than 60 coins. If you aren't comfortable counting, then just get as many coins as you can on the bottom row and lose 1 second for the textbox.
Select bottom option when prompted by Toad.
Collect 4 frog coins and 13 coins.
Go left at branching path
Go right of the hole
Bounce off rock to get Frog Coin
Go right at branching path
Collect the first coins on the top row. Bounce off the first barrel.
Do not bounce off any barrels after the 1st. Stay in the bottom row.
Collect only the first 3 coins in each set of 4 coins in the bottom row. If there are less than 4 coins in a set, grab them all.
Exception: If you have to jump over a fish during the 4th coin, it's OK to grab it.
(video credit: pidge)