Your comparison between the two attempts is really helpful. I can see why you prefer the cleaner lines in the first version, but the second attempt also shows that you were actively applying what you learned from the demo. Searching lines can be useful during the construction process, especially when you're trying to understand proportions and form. With more practice, you’ll likely become more confident in placing the initial lines, which should naturally reduce the amount of searching. Overall, great progress, and I think comparing your before-and-after studies like this is a very effective way to track improvement.

I agree with you, I think your lines look much cleaner in your first drawing. I really like the lines you chose to design the shell in your first drawing as well. I think what's missing from that first drawing are more structural straight lines to anchor all the curves. You did a better job using a mix of CSI lines in your second drawing. I think a combination of the two taking the best parts of each would be a perfect snail!