That's really good, Jack. I notice your skins have the teeth on the right and tongue on the left. When i save a skin in People Putty, it's just the opposite. What's going on, does it really matter?
Another question, how do you create .htr files with your own background? I don't know how to do that.
Sorry, not to be answering for Jack, but here are your answers in brief. Jack and Nige are far better qualified to give you detailed answers.
If you don't flip the teeth and tounge, you will notice your haptar has no teeth or tounge. You can flip the whole .jpg but you will be getting a miror image of your artwork and there is such a thing as right eye and left eye. I normaly might try cutting out the entire "eye bar" that is a rectangular cut that includes both eyes. Then I save that.

Next is where precision comes in. I usualy do a cut between eyes or on some, between the squares that are there beside most eyes. Then horizontaly flip and line up by eye - my eyes- paste back into eye bar. Too far up, teeth and tounge are recessed. Too far down, they stick out to far. This generaly works well for most. For absolute perfection, cut out just teeth and tounge marked with four dots at centers just off of teeth and tounge side and top and bottom center. Cut through centers of dots and flip. Position teeth and tounge so that dots come back together and then paint out dots and then paste back onto the flatfile you are using. msPaint lines them up automaticly, then just click save. Oh yes and don't forget to save your cuts as save as charactername eyes and eye cuts or you will lose your oringinal flatfile that you got out of P.P.
As for backrounds, if you want to use it in Hal, just add the .htr to character page and also the backround pic with name changed to characternamebackround.jpg . If you want to put the .htr up for download on savefile or somplace like that,I'm not sure enough to say how, but I'm sure Jack will answer you. I just wanted to give a quick start for you and I hope my answers aren't to vague.