Depends on why you don't finish things. Often times, it's probably a mental attitude that's a road block.
If you quit when things get hard, maybe you need to realize that hard things are hard. Anything worth finishing will require you to bleed.
If you quit because you have to "feel like it" to work, you should work even when you don't feel like it. Hard things are hard, and nothing would ever get done if people did it only when they felt like it.
There are many reasons why people aren't finishers. You need to find out why, and then figure out similar people that have overcome it and the specific tactics they used to overcome it.
To add to that, this is how I get through the times when I don't "feel like it": I tell myself I'll just sit down and get something done. It doesn't have to be a lot, but I have to sit down and accomplish something. Even just chipping away at small pieces of a task can add up over time!
If you quit when things get hard, maybe you need to realize that hard things are hard. Anything worth finishing will require you to bleed.
If you quit because you have to "feel like it" to work, you should work even when you don't feel like it. Hard things are hard, and nothing would ever get done if people did it only when they felt like it.
There are many reasons why people aren't finishers. You need to find out why, and then figure out similar people that have overcome it and the specific tactics they used to overcome it.