Hey Primrose,
You know that sort of afternoon light, where you go outside and it seems like even the leaves are shining and everything is somehow enhanced? That sort of light occurs early in the morning, not long after dawn, and in the afternoon. It's especially obvious on a cloudy day just after a thunderstorm, when the light peeks through, the air is clear and everything is ... more alive somehow.
If you can take photo's at that time of day, yours soaps will look just that bit more vivid. Try and get the light coming from just over your shoulder, or from one side or the other, so that you are looking through the lens at a soap that is naturally highlighted.
Use a pinpoint focus, and set it to somewhere about a 1/3 of the way down the bar of soap. Try focusing on different colours around the one spot, to see which gives you the best overall colour for the soap.
Use portrait (as someone has said) ... it's like you are taking a "face" photo of the soap - a lot of camera's will not make the background as vivid. In your pictures, it's like the setting is for a barbeque in the backyard, where you want everything to get a little bit of the focus ... you don't want your soap pictures to have that much detail - it's got to be all about the soap. It doesn't matter that the purple flowers in the background are just colour with the idea of you being in the garden ... that's as much background focus as you need.
Even outside, get a couple of spotlights on your soap to chase away shadows, but watch you don't wash out the photo (where everything just looks blurry whiteness).
Figure out what you do different when you photograph your kids ... your photos of those are good (the last one with the 3 babies looks like a really good "snapshot", but the colours are vivid like you want for your soaping photos - even the hay looks fresh and interesting.).
In the photo's you already have, go through them and circle where you can see the focus ... you'll be surprised with what you end up with. This task will help you get your eye in. What you are aiming to be able to do is choose the part of the soap that you want to be sharp and clear ... to choose the focal point of your picture.
Practice taking the same photo over and again a few times, changing only where you try and make the focus ... see what differences you can make with just that change (take 10 to 15 photo's of the one soap, moving only the camera focus, repeat this from 3 to 5 different angles ... pay the most attention to where the light is coming from, to work out the difference in the effect on your soap ... in the 100 or so photo's you end up with, you will get about 2 that stand out. Find out what it is that you have done that made them stand out).
Get up close and personal to your soap ... leave only just enough room to get the whole soap in ... and check out different angles again.
Always watch your background. Sometimes a tiny detail can throw a person out of a perfectly good story ... that's what you are doing, you are selling a story, in pictures.
Try using a camera stand. Most camera's have software to counter shake, but this adds a slight blur (softness) to your photo - you'll notice the change in sharpness if you use a stand.
I have tried the proper DSLR camera. I've tried my smartphone. I've made a DIY home light box. I've tried props and without. I've read hundreds of blogs, tips and tricks, watched you tube clips etc. I still dont really understand at all how to edit them. 
