Fitness today

Did the usual weights :-) I'm fairly certain that I am not doing the butterfly properly. My frame is too small for that machine, no matter how I adjust it. I think I'll start exploring other options for exercising this area.
I did make one adjustment, Instead of standing to do the pull downs, I am now seated and am using a crooked bar. Pardon the lack of technical terms, but I don't know what half the stuff I'm doing is called :-) This change allows me to do 90 pounds vs a lighter weight.
Gym was busy today, probably because of everybody's new years resolutions. I did 27 minutes on the stair climber. Why such an odd number? The first 7 were spent trying to figure out how to program it. I'd get it going, and it would shut off! So, I switched machines and did 20 minutes. I kicked my butt! I'm used to the elipticals and treadmills. I might have to use these more often :-)
After a majority of the folks left, I was able to jump on a treadmill. I walked between 3.5 and 4 miles per hour, mostly 4 mph which is fast as I could walk without jogging. My calves would get tight and I'd have to slow it down to about 3.5 for a minute to stretch them out. Any of you out there know when your lower leg muscles quit tightening up?
I off to work on my core. I will also do some skull crushers as i'd really like to eliminate that flab on the back of my arms. As far as dumb bells are concerned, I own 2 10# weights, a 15# weight, and a 25# weight. These are becoming a little too easy and am wondering if any of you have creative solutions for making weights at home? Trying not to go out and buy any....