Hi all,

I'm very new to making pixel art myself but we started on a game we want to make and so I have to understand and learn it.

I made some stuff but something seems odd with it but I can not figure what exactly.
My guess it that the light and shadows that  I try to apply are just not good.

I read about it and tried to follow the advices I found but still I can not get it right...

Before we start, I also have to admit that I'm not that creative so what I do is for example if I need a car I Google for a picture of a car and then use it as the template for my resources. That means that perhaps something is also wrong with my borders of the sprites.
Also with the borders, I'm not sure what is the best practice here, I always use black lines but I saw that many are using darker colored lines instead so when to use what and what's more common?

Anyway here are some examples that I made and feel that something is wrong but can not really figure what it is

A mushroom house


A car


A front door


A tree I made (I feel this one looks quite ok)


Who can give me tips what's wrong and how to improve it?

Thank you all and many greetings

Kroan