hey, just a question, how long do you spend on modelling something? And any advice to get better? Just asking as im interested

How long do you guys spend on a model/something your making? i know this can vary from what it is your making and the complexity, whether its a prop, weapon, character, foliage etc. Also, any tips to get better? Thanks

I am asking this as someone who does games art at college, and just want some advice :)