I would think that showing both from above is the best way, because it is the only way to show perspective if you choose not to show an arm.  Here is an example from ASL for "swim".
 

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From: Stefan Wöhrmann <[log in to unmask]>
To: [log in to unmask]
Sent: Sat, June 12, 2010 4:14:21 PM
Subject: spelling question

Hi Val and friends,

 

I am playing around with some spelling problems –

 

I am interested to see your suggestions how to write this: stretched left arm forward while the right arm (fist) moves to the breast.

 

I do not like the option to combine to different perspectives – but how to make clear otherwise that the left arm is stretched if not shown from top view?

 

 

Stefan ;-)