Skateboard crash joke = a start.
Okay, let me explain something. It's not enough to just put content in your cartoon. People just walking around doing stuff is boring. You need to add drama & comedy to this. As it is it's just a bunch of painfully slow scenes with painfully obvious conclusions and painfully boring dialogue.
Or to put it another way, here's what you're doing right now:
<Title Screen>
Hamish: I'm hungry.
*Hamish fixes a sandwich*
Hamish: "Great, now I can eat this sandwich!"
*sandwich falls on the floor*
Hamish: "Oh no! How will I eat my sandwich now!?"
*Hamish picks up the sandwich, blows the dust off of it.*
Hamish: (Insert really obvious pun that nobody laughs at. For good reason.)
<Ending credits>
It's boring because 100% of the things that happen in this cartoon were totally predictable. You need to mix things up a little more.
DRAMA:
*Hamish makes a sandwich and starts eating it.*
*Robot runs in* "Sir! Don't eat that sandwich!"
*Hamish looks at the half eaten sandwich and starts panicing*
Hamish: "What!? Why not! What's wrong with it!?"
Now the audience is in suspense. This is because the audience doesn't KNOW yet what's wrong with the sandwich. Like Hamish, the audience is anxious to find out what was wrong with the sandwich.
This same scene would NOT be dramatic if you already SHOWED the audience a bad guy poisoning the sandwich ahead of time. This is important. If the audience already knows there is something wrong with the sandwich, then they will EXPECT this entire scene so you mgiht as well skip it, or surprise the audience by doing the opposite of what the audience expects:
HUMOR:
*villian poisons sandwich*
*Hamish picks up the sandwich*
Robot: "Sir! Don't eat that sandwich!"
Hamish: "Oh my god! You're RIGHT! This is that crappy low-carb bread!" *throws sandwich in the trash*
You can further mix it up by making random, silly things happen. This could be humor or it could be suspenseful action, or both. Either way is fine, as long as it's UNEXPECTED!
RANDOM DRAMA:
*After the sandwich has been thrown away, the trash can starts to glow. We do NOT show the audience what's happening in the trash can, we just show that something weird is happening and cut away. Later, after the audience has forgotten about it, it'll be that much more surprising when a SANDWICH MONSTER attacks, and the audience will realize what the trash can scene meant.
RANDOM HUMOR:
If the sandwich monster wasn't random enough, maybe Hammish goes on to make his next sandwich out of two playing cards and a packet of hot sauce, because that's the only other food he could find in the house. Then when he tries to bite down on it, the packet breaks and the suace squirts out and hits the villian, who was hiding in the kitchen and maybe muttering something funny about why the poison didn't work.
INVERSION: (Do the exact opposite of what we expect)
*Villian poisons sandwich*
Robot: "NO! Don't eat it!"
*Hamish eats it*
Hamish: "Hey, that was a pretty good sandwich."
(This is funny because we were expecting him to be poisoned and he wasn't.)
After a surprise has been revealed to the audience, you have to explain why the surpsising thing happened. Either have the character wonder about it:
Robot: "Um, sir, don't humans die when they eat poison?"
Hamish: "Yeah, what's up with that?"
*They go study the crusts of the sandwich to try and figure out why*
Or have someone else figure out what's going on:
Villian: "Wait a minute... That's wasn't the poison I put in the sandwich! It was..."
DRAMA: "My new Monster Potion!"
COMEDY: "Laxative!"
RANDOM: "Coupon Spray!"
(If the sandwich was spiked with something random and silly like "coupon spray," now the audience is wondering what the heck coupon spray is. Show it in the next scene!)
The trick is to ask the audience a question, or pose a mystery, THEN answer it LATER. If you show the cause first, then the effect should be something other than what the audience expects.
You can learn more at www.tvtropes.org
Good luck mate!