TS : Why are u shooting at High ISO when u r on tripod?
Since u on tripod, rule of thumb is to use base iso (where we can get 1. least noise 2. most dynamic range 3. highest iq)
On top of what nai meh and francis mentioned above.
1. Mirror lock up helps if you do not have an cable release.
2. Use of black card helps also with rgds to long exposure. To fully minimize the camera shake caused by the mirror mechanism, cover front of ur lens with the black card before you release the shutter (via a cable release)
As the mirror flip up, pause for a few seconds before you uncover the black card, to make the exposure.