The most easy way to fill LC in cell.
Place the wide opening of the gap in up direction. Now tape it very near to the top of the slide to avoid wastage of the sample.
This setup is tilted and placed on the hot stage.
Now heat it extremely hot. Check by dropping very very less amount of sample on the opening. If the sample becomes isotropic instantly carryon by adding little-little sample. Within 15 min complete cell got filled.