I bought a digital watch recently that beeps on the hour, prompting me to do an RC. In one dream my mum reminded me to check my watch and I had a flash of awareness that died down after a few seconds. Last night in a dream, I looked at my watch and it was as I expected it to be, so I didn’t really attain lucidity. Why are my reality checks failing?
Because if lucidity would mean only RC’s then it would be easy. RC’ing is just one part of the bigger picture here. Doing RC’s is not enough to realy achieve lucidity. Like you said yourself they are partially effective. And that’s what you gonna get from that partial effect.
They may sometimes remind you that you are in a dream but if there is no more lucid mind involved then just reality checking then you will probably fail…
And also reminding yourself to RC when you watch beeps is not that good. Because you will get accustomed to pattern on beeping and later you won’t even mind it. Specially if you don’t perform RC’s like you should…
Do RC’s whenever you think about them or dreaming, if you don’t have those moments then you are not dedicated enough to become lucid dreamer…
I just find the beeping brings the idea of doing an RC in my mind, otherwise I might forget to do one, so surely it is good for making me remember? Do I just need to do the RC with more meaning?
You need to do RC’s with a questioning attitude.
If you just do them mechanically without any real concentration then they will just become something that you do in dreams and then forget about.
Try this - stop for a moment, and observe your surroundings.
Remind yourself that you could actually be dreaming, but that you have been too deep in thoughts to really notice it.
Now do different tests of your surroundings to really prove to yourself that you are awake, and do not stop this until you are 100% sure that it isn’t a dream.
These tests can be anything, as long as it’s something that is impossible to do in real life.
It doesn’t necessarily have to be tests that you read about on the Internet, you can make up a bunch of your own RC’s as well.
Basically, if you attempt something that is impossible to do in real life then it qualifies as a RC.
This is especially important when you wake up in the morning, because then you have just started the day and haven’t had the time to get a “feel” for if you are awake for real yet.
It’s good to have some kind of the reminder but I wouldn’t suggest one like watch. Well at least not the watch by itself. It’s just not enough. Because then you might see a walking dog with human head and you won’t RC because your watch didn’t remind you. You see what I mean?
Oh, and what Laurelindo said! 
When I practice awareness I usually pretend that real life is a lucid dream; this mindset automatically makes me use all my senses, because the fantasy that I already am in a lucid dream makes everything around me feel a lot more interesting.