[Batfish]

The absolute best way is to buy the expensive crimping tool from Anderson. I, however, use a crimper I got at Home Depot and just make sure I take my time to do a good job.
That article will show you what a good crimping job should look like with the connector. Regardless of the tool you use, you should strive for that look.
Once I have the connector crimped, I put the housing opening-up on a table and place a precision flat-head screwdriver on the back end of the connector to force it down into the housing. I just keep pushing down until it clicks into place. They also sell an "insertion tool", but my method works well for me.