1
Can you describe me your new flat?
Can you describe your new flat to me?
Use describe something to someone: ‘She described the new flat to me.’
Do not put the listener directly after describe. ‘Describe me’ would mean ‘say what I am like’, not ‘describe something to me’.
2
In my email, I described about the problem.
In my email, I described the problem.
Put the thing you describe directly after describe. Do not add about: ‘He described the problem clearly.’
See EXPLAIN