Straight Lines Please

I have been printing consistently for 5 months now. There is such a huge difference in my prints from when I first started! I am still a novice compared with those who have mastered the letterpress trade, and I can only become better. The hardest technique for me, is knowing how and when to adjust packing for an even, relatively deep impression. There are discussions on Briarpress about how deep an impression should be- just a "kiss" to the paper or an obvious indentation. A veteran printer will tell you that one should not even see an indentation in the paper. Modern letterpress junkies will tell you their clients want to see and feel the texture on the paper, and that is what they are paying for. If they wanted offset printing they could have paid for that, but they want letterpress and would like to see that it is indeed, pressed into the paper.

A few things I need to play around with:

* Registering a straight line to be straight. Ever draw a line with a ruler and it ends up not straight? Sometimes I feel like my eyes are playing tricks on me and my print looks straight, but to the graphic eye, it's not. What is the best method of measuring and registering a straight line? Any tips on technique are welcome.

* Cutting a straight line. If you look at the posting of my newly acquired Challenge 19" Guillotine, you can see that this is one serious paper cutter. My only issue is, when I cut down, the cut line shifts and ends up crooked. I put about 25 sheets of 110# paper, maybe I need to decrease the amount per cut? Or maybe I need to tighten the grip on the paper before cutting? If I can master the art of cutting paper, I can do more cut downs on my own instead of sourcing it out and paying a fee.

If you have any tricks of the trade, please leave me a comment. I could use some advice on these!