I can't remember where I learned this, but putting on my workout clothes when I don't feel like working out somehow gives me just the boost I need to get me out the door. It works 99% of the time. So keep those tanks, tees, sports bras and biking shorts ready to go. Once you're dressed the reasons not to workout suddenly disappear.
Looking your best means having clothes that are comfortable and appealing to YOU. You're more likely to put them on, if YOU think you look great.