Use fixed range charts so that you are always looking at the same
geometric configuration. Dynamic charts can be very deceptive as they will cram the daily range into the available space on big moves which distorts the angle of your trendlines or whatever indicators you are using. When your charts are always the same you can then, eventually,judge when you have a trend with your eyeballs. If you want to use an indicator the macd is pretty good as it is absolute rather than relative. A lot of people use ADX but these are only giving a number to what you should be able to see with your eyes after some serious screentime.