Ok, first of all you have done a good job, they are all the same length and not too thick. As Sara-Jane said, the side edges could be more streamlined rather than "A-line" they need to look like they're growing straight from the nail bed, maybe even a little tapered in. They are a little bulbous in places and the area closest to the cuticle could be blended more. If I can find a diagram then I will post the picture. The best advice I can give you is to perfect your craft before working on your speed, skill before timing is very important. Methodology is also important, have the same method/routine for each nail from filing the natural free edge to application of tips to application of acrylic to blending and shaping acrylic. You could also consider going to a nail technician in your area (reputable) to see how they do your nails and watch them closely. I hope that helps.
Your nail art is fab btw.... I love glitter nails x