It takes time to get to know your characters so don’t rush it. After a while you know exactly what they will do and won’t do so as I get to know them better I sometimes need to make adjustments at the beginning. Thinking back to some of the earlier characters, it isn’t always the ‘nice’ ones that stick in my head.  On the subject of rejection, it is hard to take and don’t I know it. Your work is precious to you and it is hurtful when somebody rejects it. Take note if a comment is offered and act on it and do persevere. If you are writing short stories make sure that one is always ‘away’ with a magazine or a competition to keep your hopes alive.