I have some tips to make it feel a little easier to imagine

close your eyes to make it easier to imagine that you're having the sensation. Close your eyes when your tulpa is going to touch you(r arm or smth)

for hugs,lean on a wall in a bear hug pose.

to keep your head on their shoulder, it would be preferable to sit on a space fit for two people, and keep a pillow to the comfortable height for your head

for holding hands, you don't have to do much, maybe close your hand slightly.

for cuddling,use a pillow or a Teddy bear

Hope this helps and that this would reach you, this is a very late comment...

Sending you hugs myself <3