[knowledgepower21 (OP)]

Mix everything together:

1)

500 ml almondmilk
1  Avocado
1 lemon juice
1 walnut

2)

3carrots
1 beetroot
1 apple
1/2 cucumber
100 ml water
3)

lettuce
2 Tomato
2 celery
100 ml Water

[Bored chemist]

Other flavoured water drinks are also available.
Dehydration can certainly be a cause of a headache and the smoothies would help.
Though, given the noise   from smoothie makers, you would probably want someone else to do the work.

[ScienceMann]

As our diet in general has a huge impact on how we feel, it is plausible that just as some foods can simply make you feel unwell, others can help us feel better. I know, for example, that in addition to drinking enough water, magnesium can play a role in alleviating migraine. Bananas and avocados, in particular, contain a lot of magnesium. If you prepare a smoothie with these, this can lead to the relief of headache/migraine