Nice work so far, My advice would be to look out for values, some of yours seem to be a little to dark, still life looks great by the way.
you are making some fast improvement. keep it up!
Jeez ZitaX man you're really improving! Your last couple of greyscales are right on key! your rendering technique is really refining now they're almost starting to look real
Keep up the Excellent work!
Nice to see so many studies! really inspiring.
There are some things I want to point out though that are good to think of.
First, in your studies from life, especially in the shadows of the fruits you have very soft edges. Try to paint with harder brushstrokes in key areas such as the silhouette of the fruit and the shadow. A stron hard silhouette will make the fruit much more readable and a hard shadow will 'ground' the fruit. As it is now they are floating in the air rather than resting on a flat surface.
Did a quick paintover to show you what I mean, notice how I flattened out the shadow, made the edges harder and made the shadow darker underneath the banana.
Also, in the shadowy part of the banana the yellow hue was a bit cold, and it gave the banana a 'muddy' look. When the temperature of a colour is too cold in relation to its surrounding colours, it looks like mud. Thats why shadows that are painted with black over a hue often look wrong.
To make the shadowy area of the banana feel more natural, I went down to warmer orange-browns instead of the yellow-browns.
When you begin to study light and colour-relationships you will start to understand these things and make decisions based upon that. For instance.. I know that the light from a table-lamp is warm, and I assume your banana has been studied under such light. That tells me that the warmth of the light reflects upon the table and back into the shadowy area of the banana and renders it warm. Makes sense?
second, your valuestudies are looking good, but you're still not thinking in volumes. What I mean by that is that you don't divide your values into shadow, midtone and light. Here's a quick example from one of your studies:
First off, the lighting is not good in the photograph, the lights are too strong so you don't get clear shaow/midtone/light relationships and nice castshadows. Anyhow, see how much brighter the values are in the photograph compared to your study?
All of these things will become easier to understand the more you paint, and trust me, it'll happen sooner than you think. You're painting a lot and doing it well, so just keep it up. I hope this information hellps you. Keep it in mind from now on when doing valuestudies and rendering shadows - harder eges, higher contrast and brighter values.