How long could you sit there and mine for? Maybe an hour and a half? What about fletching, pretty simple no brainer task--could do it for 2 hours. Short periods like that decrease chance of ban. If you can do something away from people, do it. Don't bot one day at 2am for 3 hours then bot another 4 hours at noon. Try and stick to a schedule...yaknow.....like a real player would have. Also, don't aways do the same thing. Get yourself 41 mining then do some woodcutting for example, don't power out 70 mining and nothing else.
Also the biggest thing....private scripts. As much as scripters say their scripts run uniquely for each player, there is only so much you can change. Those small differences leave patterns that link hundreds of players, even if the playing style is a bit different for each instance.