Yama:
Yama in the Hindu mythology is considered the God of death. Yama is described as mounted on a black buffalo. He holds a noose in one hand, in order to catch hold of his victims. In the other he holds a mace which represents his weapon. He is the son of Vivasvat (sun, surya) [...]

Indra:
Indra is said to be the king of Gods. He is more often known as the god of thunder storms, wielding a celestial weapon, The Vajra, a lighting bolt. Indra is described as reddish in complexion with two or four hands. He is the son of the Sky god and the mother earth, Prithvi. [...]

Ganesha:
Ganesha, Gajanana, Vinayaka, eka danti are some of the names he is known as. In the shiva purana it is said that Goddess parvati created ganesha out of the dirt of her body while bathing and assigned the task of guarding until she finishes her bath. Meanwhile lord shiva returned and was furious as he [...]

When both the hands in Ardhachandra hasta are placed over one another and only the Thumbs are interlocked we get the Garuda hasta.

Lets take a look at the viniyoga shloka
Garudarthe Viniyujyate
Its says that this hasta is used to denote a Hawk.
It can also denote birds flying.

While in the Simhamukha hand gesture, the Middle finger and the ring finger is bent to form an arch. Also the thumb is slightly bent. Thus a “C” shape is formed with the Middle finger, Ring finger and the thumb. The other fingers are Erect.

This Hasta can be used to denote:

A Bracelet
Holding of [...]

If in the Kapitta gesture, the Index finger is kept straight and the thumb is slightly moved up, we get Ardhasuchi hand gesture.

lets take a look at the Viniyoga shloka of Ardhasuchi
Ankure pakshishavaade bruhatkite niyujyate
It says that Ardhasuchi is used to denote

Sprouts
Chicks or small ones of the birds
Big Worms

Hold Ardhacandra in the left hand, palm facing up. Hold shikhara in the right hand and place it on the left hand.

Lets take a look at the Viniyoga Shloka (uses)
viniyogastu tasyeva shivalingastya darshane
The shloka say that this Mudra indicates a Linga of lord Shiva. Linga means sign, mark or symbol. Thus [...]

When the right and left palms touches the left and right shoulder respectively in Mrigashirsha mudra we get the Utsanga hasta.

Lets take a look at the Viniyoga shloka (uses)
Alingena cha Lajjayamangadadipradarshane
balaanaam shikshane chayamutsange yujyate karaha
The shloka says that Utsangha is used to denote

An embrace
To show Modesty, Shyness etc
Display of Armlets and other such ornaments
Coaching children

Return [...]

When both the Palms are joined together at the little finger and slightly hollow at the centre of the Palms. The inner palm facing up.
The other way to look at it would be when two Sarpashirsha is held together we get the Pushpaputa Hasta.

Let take a look at the Viniyoga Shloka (uses)
Neeranjanavidhau variphaladigrahanepi cha
sandhyayamardhyadane [...]

We get the swastika pose when both the palms in pataka are crossed at the wrists.

lets take a look at the viniyoga shloka: (uses)
sammuhagamane tunda darshane shankha purane
anganam motane shakhonamane cha niyujyate
The shloka says that swastika denotes a Crocodile
My imagination says it can be used
To say “No”
To show a blocked road or a passage
To [...]