You could create your own rubic for grading, including best effort, clear hand writing, spelled correctly first time… what ever is appropriate for your child’s ability pick those as topics for the rubic and then grade from that. So best effort could be 70%, clear penmanship could be 20%, and no mistakes 10%.
The topics for grading could be different things depending on grade and ability as well as goals for the year. For example if the student has rough penmanship, but you know can do better (not physically unable to improve) a goal would be to improve penmanship so that might take a high percentage on the rubic to encourage improvement.
Within your rubic you could choose how to grade it, knowing best effort was used or if it was rushed and things like that.
Those are just thoughts to get the ball rolling, hopefully others have some suggestions as well 🙂