Published on 12, July, 2020
I struggle big time with dehydration. I know it's a common problem for autistic people. It's something I've always struggled with since I was a child, during the hotter months always filled me with dread and still do.
I also don't feel thirst cues
I agree with Iain, timers are good as are water bottles.
Other things I find useful is using other indicators. You've said that your lips go dry, maybe when you notice this you can use it as a trigger to drink water.
The other important thing I find is having set times to go to the toilet (at least twice a day, preferably three but that can be worked up to) and use the urine colour to indicate how hydrated you are. If it's dark in colour, drink at least a full glass of water.
I got a lot of dehydration headaches, that is also something I used as a cue, If I got a headache I had to drink a full glass of water.
All of these other cues may be more delayed than the traditional 'thirst' cue, but they are still cues, and you can tune yourself into those instead.