Press to wake on apple watch

Hello.
I have an apple watch sport 38 milimeter.
I read that it should be possible to wake the watch by just pressing the screen, but it doesn¨’t allways work. Am I pressing too softly am I supposed to do a force touch to wake it?
I can use raise to wake, but that takes a lot of battery, I have heard. I haven’t tried that much but am writing ackording to what has been said about battery useage.
Am I doing something wrong?