I don't find blending tip a problem, but I know many do. There is a knack to it, it's pretty hard to explain, easier to teach in person (like most things nail related). I blend 'up' not 'down' or 'across' - so I start with my abrasive on the tip (towards the free edge) and stroke upwards towards the cuticle. This means I can put a fair amount of pressure on the abrasive as I'm nowhere near natural nail, my abrasive is on the tip at all times. I hold my abrasive almost diagonally across the nail and sweep upwards, lift the abrasive, turn the nail a few millimetres, do my next upward stoke of the abrasive, working my way across the nail from side wall to side wall.
I found 'downward' strokes made me scared of hitting the natural nail so it made me too tentative, so I was buffing and buffing and getting nowhere. I can blend a tip in just a few strokes now. It took a while, don't misunderstand me, it didn't happen over night, but like with most nail techniques it suddenly clicked one day.
Practice, practice, practise - a trainer hand is your best friend. and if you can blend a CND Formation tip you can blend anything!!