Oops I didn't mean to sound blunt, but I'm really sleepy this couple of days..
Great! It's looking better bl in blinders are really pretty, esp the b
now you can work on consistency. There's some math to this.. let's go to the angles of 52deg slant and 30 deg connecting slant.. make sure that the connecting slant has a slight curve in them. Loops letters should all have loops that look the same in size, angle, thickness etc. - the loops on l, b, h, k.. and j, y, g, z too.
On letters like a, there's a gentle n shaped curve upwards very slightly, following the curve of the oval in 'a'. when you end your 'a', the connecting curve should have a slight u shaped curve (compare your 'a' and 'n's, some of them have sharp v shaped connectors like a tick ('horse', 'I am', the 'n' in blinders'). you should keep in mind that they should lead in to the next letter, and should not appear to have a break in the middle to achieve an elegant look. As such, it's gonna be a bit like chess, where you gotta envision your next letter and how they should look when joined to prevent breakages in the connecting lines. or you can make it look less obvious
What amy mentioned about drills, there are portions where practice books ask you to connect a letter to the next random letter, like ab, ac, aq, aw, ak47, so you can get used to these letters before writing out longer sentences.
'a' should look like 'd' if there's a ascender to it, which means the size of the oval in a, d should be the same. o is slightly narrower, and as for shading, it's completely arbitrary. The shadings in spencerian serve to create some visual interest in the piece, and it certainly wouldn't look so appealing if one particular word like 'bookstore' <-- my fav word to write had shadings on all of the letters, compared to the rest of the sentence that is barely shaded at all. From far, the aesthetic of this would look like one blob of ink. So it's better to space them out, like stars in the night inky sky..