The variations tend to come from
1. The random number seed (I like rng(4151941))
2. The random division of data
3. The random initial weights
I generally use defaults except for a range of hidden node sizes
h = Hmin:dH:Hmax
Then for each value of h, train Ntrials (usually 10) models.
Sometimes a perusal of the Ntrials x numel(h) matrix of results causes me to change some parameter(s) and repeat.
I have posted zillions of examples in both the NEWSGROUP and ANSWERS. My tutorials are in the NEWSGROUP.
I always start using all defaults to get the lay of the land.
Reasonable searchwords to include are subsets of
neural greg Hmin:dH:Hmax Ntrials
Post selected code with comments and/or error messages if you have further problems.
Hope this helps.
Thank you for formally accepting my answer
Greg