So now to make the 'morph' transformation happen there are two ways to go about it. If you are just starting out, you can use the existing morphs that come with the figure or those you have downloaded. If the morphs are included on the figure, such as with Daz Vicki2, you can just turn the dials and save your result in the pose library. This way is very easy and the pose (.pz2) can be distributed or sold. If you use morphs you have downloaded, these belong to the artists who created them and they generally cannot be distributed or sold without permission of the artist but they can be great for personal use and for rendering.
Then there is the second way, creating custom morphs. This is the method I use. There's a lot to be said for it. You can get a more precise look, your character won't look just like everyone else's and most importantly you will learn more by doing it that way. Custom morphs can be made in Poser or with another 3d program. The way to make morphs in poser is to use the 'magnets'. The magnets are very intuitive and easy to control once you get the hang of it. Don't be thrown off by the peculiar shape of the giant magnet, it is possible to get very precise results from this tool which can be viewed real time in poser.
To make a magnet morph you begin by selecting a body part and then go to the 'object' menu, select 'create magnet'. You will see two items appear, one is a sphere and the other is a giant horseshoe magnet (Don't ask me) on a yellow base. Anyway the sphere represents the area that you want to be effected by the magnet. It has a gradual falloff so that the effects you create with it will be smooth and organic looking. This falloff zone can be manipulated by double clicking on the sphere and selecting 'edit falloff graph'. You'd use this if you wanted a more dramatic falloff effect rather than a well blended one for instance. I don't edit the falloff much myself. The 'Magnet' itself is the tool that you use to scale or translate the area within the sphere. The magnet base is how poser determines where the effect starts. (This bit is hard to explain, the best thing is to experiment with it 'till you see the effect.) Once you get the desired distortion you just select your body part, go back to the object menu and select 'spawn morph target'. Type a name in the field like 'big nose'. A whole character is usually gazzilions of these morphs combined, the figure should be saved as a cr2 when you have it how you like it, or periodically so as not to loose your work. Then you need a free utility called 'Morph Manager' to combine them all into a single morph on each part. You can also use the Hierarchy window to delete individual morphs after you've combined them into a single character morph but I find it awkward compared with the Morph Manager utility. You should probably save your individual morphs to use in other characters later. The easy way is to leave them on your figure and save as a Cr2, you can use Morph Manager to transfer them to a new figure as needed. You can save the morphs as .obj but that's very time consuming and impossible to 'browse' in that format. If you leave them in a cr2 you can just load it to view the morphs. So that's the tools but of course there's more to it than that.
The first instinct is just to do what looks good to you, and more or less that's all there is to do, but it pays to analyze exactly why certain things look good before using them. I'm going to talk in terms of faces but the same principle applies to any part. The face communicates a great deal of information to the viewer. I have read a lot about the meaning derived from various characteristics of the face. Some indicate youth or age, some indicate the presence of testosterone (masculinity, like a square jaw) some of estrogen (flat brow, oval face, big lips etc.). Then there are those things that fall into the category of facial expression. If the brows are drawn close together the face will appear to be scowling whereas wide set eyes and brows look placid and trustworthy etc. Facial characteristics absolutely all mean something, or evoke a certain predictable response in the viewer. I could probably write a whole volume on this alone but a girl has to keep some trade secrets ;-). Mainly it is important to try, to the best of your ability, to make sure that what you are communicating with your face is a message that makes sense.
Next is proper proportion. It is helpful to use the time honored methods to figure out proportions. The basic figure is 7 to 8 heads tall. Each part should fall in a specific place to be in proportion. It's OK to make a character that's out of proportion but remember that you are communicating something to the viewer with each variation from the norm. For instance fashion drawings often elongate the figure so that the legs, instead of being about 4 heads tall are made up to 7 heads. That's also done a lot in anime. Anime is a good thing to study if you want to make younger looking characters. Another way to get your characters more realistic looking is to try to account for the bone structure below the surface, especially with noses and jawlines. In other words- if someone dug up the skull that would be under this face, would it be classed as human ;-) (or whatever your intent)? Always make sure it looks good in profile and 3/4 angles too.
Try to account for your figure's muscle structure. This can be a bit of a pain and the daz figures are mostly correct with few exceptions. If you are unsure about muscle structure it's probably best to leave it alone, because any bulge the eye sees that is not where a muscle would be is picked up as fat or possibly an alien life form about to emerge ;-). On the other hand the best way to learn is by doing. I strongly recommend 'Human Anatomy for Artists' by Elliot Goldfinger as it has bone structure, muscles shown relaxed and flexed and from several angles each. Worth 10 of every other anatomy book I've seen.
Another way to express a character's individuality is with clothing or costume. If you can't make clothing for Poser there are lots of items already created that can be adapted to suit your needs. Last is texturing, a custom texture can give your character a new level of uniqueness, there is no substitute for a good texture. There are lots of tutorials available on the specifics of texture creation so I'll leave it at that for now.
I'm sure there are as many ways to create characters as there are people and the most important thing is always to follow the dictates of your own personal muse.