- Don't wait 60+ episodes to decide on a goal or direction for the main character. Either give them a direction from day one, or deliberately write them as aimless. If the character is aimless, make it clear that they're aimless and that they're struggling with their lack of direction. It's essential that this is established as early as possible, otherwise it's just wasted time that could have been used more efficiently.
- Make the characters struggle. It's way more fun when a character has to struggle to achieve success, or has to work hard to get something. A character who gets something easily, without working for it, or without struggling with it, is just not a very interesting one. It makes it hard to care.
- Create a group with a spicy dynamic. Traveling groups who always get along and are always nice to each other are boring. They can be friends of course, or maybe not even friends, maybe they're companions out of necessity, rather than genuine desire. Give me bickering, conflicting viewpoints, it's a perfect opportunity for both comedic scenes as well as character growth.
- If you absolutely need to have "filler episodes", at least make use of them. Make them training episodes, bonding episodes, flashback episodes, something that will add to the characters. Also, please no off-screen development.
- Please have a clear structure from beginning to end, or at least a rough outline of storyline for the main cast and the overall series. It's very easy to notice when a series hasn't been properly planned out, and it just reeks of bad writing.