Three things that will help and why...

If you are not happy with your transitions there are three reasons I can think of that will be the major cause.

One.
Phrase matching / Placement - You are not mixing in a good place in the song and your mixes sound a little too busy. You are not in phrase and again it sounds too busy and slightly off.

Two.
Energy Drops - You are picking the wrong types of records in your progression. Really what you should be looking to do is build energy so you would really want to try and identify what has low-medium-high energy. Once in a mix it could be suggested that once you have hit the high energy status you only drop back to the higher end of medium in your sets. More a guideline than a rule as each DJ situation may call for different measures.

Three.
Harmonic Mixing - When you feel ready look into this. It will definately make your mixes sound so much better. When keys match or are compatible they will sound so much more pleasing to the ear. Once you know this you will also know how to make songs with less energy seem more exciting when they are being mixed and it will also make you a good warm up DJ as people will feel the changes in energy and start to respond even if you aren't in a position to play those monster tracks.

Just a few thoughts.
Cheers
Nem

___________________
https://www.mixcloud.com/Calvin_Karass/