Homerun Contest

Ganondorf is easily the best for the Home Run Contest. To unlock him, beat Event 29 and then defeat him again.

An easy beginners technique to hit the Sandbag that far (with Ganondorf) is to run up to the Sandbag, use the up an A smash attack (the double kick), then use his aerial down and A. Repeat once, then either use his Warlock Punch (B) or hit it with the bat. If you want to hit it with the bat, make sure you grab the bat before you do anything else, otherwise there won't be enough time to run and grab it.

Yoshi is the character I would use, just jump and hit the bag as many times as you can and hit it with the hammer at the last second.

I use Fox, not Falco. Just fire away (with B) and smash it with the bat at the last minute. Do not use Falco because his lasers fire slower and they move the sand bag.

I use Yoshi's down and A attack in the air as many times as possible then hit it with the baseball bat. I usually get over 1000 m.

Use Yoshi's Down+A move he rapidly kicks down and does a lot of damage
Then once the time is to 3-2 have the bat then swing away make sure you
Use that bat right when you hit it you should see a light from the bat
And here a K-ching noise something like that.

Yoshi is the easiest to hit the Sandbag far. First grab the bat. Then jump and get good timing to use Down-A on the Sandbag. It should inflict at least 20%-30% each time. Do this 2-5 times which will make at least 120% or somewhere around that and hit the bag with the tip of the bat. It should help a little bit and the bag will go at least 1200-1800 ft.

Doing this will unlock Yoshi's Island and the Paper Mario Trophy.