Recently I have been reading Dr. John Mew's book and an important step for correct tongue posture that he covers is creating negative pressure (vacuum effect) in the mouth.
This enables the top surface of the tongue to stick to the roof of the mouth (soft and hard palates) and achieve constant and gentle force.
Aside from the various techniques that have been covered about this topic (such as the tongue sweep and micro swallow) tongue strength is very important to achieve this.
The tongue is made up of 8 muscles (4 intrinsic and 4 extrinsic) and when some of those are weak they make tongue posturing very difficult. Parts of the tongue are strong enough and can stick on the roof of the mouth while other are lagging behind.
Ultimately they cause the tongue to drop.
This is just one cause for poor tongue posture in addition to allot of other reason such as a narrow palate or low hyoid bone.

my story: http://www.aljabri.com/blog/my-story/
How does one differentiate between weak tongue muscles and a tongue tie when struggling to apply proper posture? Whats the solution to achieving proper tongue posture in the case of a weak tongue or low hyoid bone?
tongue chewing helps a lot for my with soft gum like 6 gums and then just pushing as hard as possible agianst the hardpalate
How does one differentiate between weak tongue muscles and a tongue tie when struggling to apply proper posture? Whats the solution to achieving proper tongue posture in the case of a weak tongue or low hyoid bone?
In moderate and sever cases it's straight forward. The tongue appears to have an indentation in the middle and the tie sticks out, but with mild cases it's tricky.
My online myofunctional therapist was not sure about my tongue so she asked me to take a pictures of my tongue performing different functions and send it to her. She confirmed I did not have any tie, but I think this shows that tongue ties don't always have a clear physical symptom.

my story: http://www.aljabri.com/blog/my-story/
tongue chewing helps a lot for my with soft gum like 6 gums and then just pushing as hard as possible agianst the hardpalate
This is a good exercise but it does not address certain muscles of the tongue. That's why after performing it for over a year I still can't do some functions with my tongue very well. My myofunctional therapist was able to point out those deficiencies after having me do some tests.
One more thing I want to add is it's not about performing any oral exercise hard but more in a controlled manner. If you go too hard you end up engaging other muscles that shouldn't.
my story: http://www.aljabri.com/blog/my-story/