Hi Mary,
I can see from your pics that you continue to improve in leaps and bounds with every figure you paint, which is what we all strive for. Well done.
I can certainly recommend using an optivsior, especially for painting small, detailed parts, and also to enable you to zoom in on areas that need special attention, such as eyes and faces.
One area that you can improve on is to reduce the appearance of brushstrokes on the surface of the figure. There are a couple of spots on the skin where brush strokes are visible, which I think detracts from the overall look of the figure. If you're using oil paints, then this could mean you're loading up your brush with too much paint. If acrylics, then you probably need to do some additional blending. Whatever your paint medium, brushstrokes can be avoided by not putting too much paint on the brush, and not allowing the paint to become too thickly layered. I hope this makes sense, and I hope it helps you continue to improve your painting, and get more satisfaction from your figure painting.
At the risk of appearing too critical, may I also suggest you avoid using the artificial foam and lichen materials for your groundwork. They look artificial and unnatural and I think they detract from, rather than enhance, the realism of your figure. There are plenty of very realistic looking materials available from various suppliers, but some of the best materials are out in your garden and in your kitchen.
I always use real dirt from my garden when creating a base for a figure. The uneven texture and irregular sizes of the dirt is more natural than the uniform sized products available in hobby and craft stores.
I find that using various crushed herbs such as parsley and oregeno make excellent leaf litter, as does tea from a tea bag. I use these all the time to create a covering of leaf litter on a base. For grasses you can use sisal rope and/ or static grass (which need to be painted) or some excellent and very realistic products you can buy online that replicate small clumps of grasses/ tossocks etc. There are also excellent paper products available which allow you to create ferns and other small plants. Federicus Rex would be my recommendation.
Groundwork is something that most modellers find challenging, and there are no right or wrong ways to do it, however just like figure painting the goal is to try to achieve realism. The more natural products you can use in your groundwork, the more real your groundwork should look. I'm sure if you want to improve your groundwork, you can find plenty of excellent SBS'd and tutorials here on pF to inspire you and teach you some of the more popular techniques.
