Your shots are cool! They need a little tweaking in the settings though to increase depth of field and focus.
The recommendation for a shutter release remote cable or infrared trigger is an absolute!
It stops any camera shake when taking the pic.
Make sure you use a tripod and shoot straight thru the glass for best focus.
Now, shoot in Manual mode.
Set your F-stop to F28.
Then set your shutter speed using the exposure meter. It is the meter that reads -2...-1...0...+1...+2. You want to shoot at about -1. Then see how that shot looks.
The shutter will be open for a longer period of time, so a tripod is a must.
Make sure you read this whole thread.....
IMO, this is the best thread I have read to date about how to take these shots....
https://www.reef2reef.com/forums/showthread.php?t=9217
Also, I picked up the 70-300mm F4-5.6 for $130(usually $230) and the external Flash for $180.(usually $300) All at Circuit City! They had Pro lenses too, but even discounted they were too expensive. There was a Carl Ziess 300mm F2.8 for $2800 normally $6,000. WOW!
They also had a 50mm 1.4 for $210 normally $320.
All in all very good deals!!!!