I prefer to use chia as a egg replacer because of taste and longer shelf life. With flaxseed I found that it gets rancid. I do ingest flaxseed but I get a small container of it due to short shelf life.

You can experiment with using more or less liquid depending on your preference.
If pudding is too runny add more chia.
If pudding is to thick add more liquid.

3-4 Tablespoons of chia seeds in a sealable container, 1 cup of liquid.
You have tons of options as far as liquids. There is pineapple juice, watermelon juice, mango juice...

1 Tablespoon of sweetener of choice (I don’t use anything because the juices are already naturally sweet). Some juice is tangy.
If I make chocolate pudding I will be using agave nectar.
Seal container and shake vigorously.
Store in refrigerator for 6-8 hours until pudding-like consistency.

My lazy Chocolate Pudding
In a small pot on the stove add
1/4 cup of vegan chocolate chips, either
sweet or semi-sweet depending on your
preference
low heat till melted, add
1 cup of plant based milk, mix very well with
chips, you may need to up the heat depending
on your stove, once it’s completely mixed well,
(you don’t want any clumps of chocolate),
turn off the stove, add
1/4 teaspoon of vanilla
1/4 teaspoon of cinnamon
1 tablespoon of agave nectar (depending on your sweet tooth, might be a little less or a little more).
mix well then add
3-4 tablespoons of chia seeds
then mix all ingredients then put in the fridge
for 6-8 hours because by that time seeds stop expanding

@Wildgreens Thank you Dani. I will add this to my recipe list. I make a lunch desert either with agar-agar powder or tapioca. Also lots of canned and dried fruits (and even some currants I soak in Gin). This might be another method. BTW, I always store Flax and Chia in the freezer and when it is time grind the needed amounts in a spice grinder.