Heat-induced convulsions is one of the best known models of febrile seizures. (by exposing rodent pups to hyperthermia.)

http://www.ncbi.nlm.nih.gov/pubmed/16950656

MES induced convulsions is frequently used models both in mice and rats. But you need equipment and a lot of skills i think :)

Chemical/medicine induced convulsions is easier to do.

I would say intra-peritoneal injection of KA or pilocarpine to rat is among the easiest ones to induce seizure. electrical stim amygdala or hippocampus can do it too. such as this one.

Biol. Cybern. 68, 335-340 (1993) Biological

A neural network model for kindling of focal epilepsy: basic mechanism

As mentioned above, you can use pilocarpine or KA to induce seizures. Scharfman lab at NKI has done extensive work on epilepsy/seizures. Moreover, they have found that you can induce seizures in limbic areas through hippocampal infusion of BDNF.

http://www.ncbi.nlm.nih.gov/pubmed/11922662