When you use template for self-provisioning, you may follow below tips:

1. Keep templates in dedicated resource pool (probably - ESXi cluster dedicated for Management purpose, not in ESXi cluster dedicated for VDC* Tenants).

2. Keep the templates in dedicated folder, use your workflow to pull the templates from that folder. Actually you will give option to choose the template to customer, customers can provision VMs using templates that you need.

3. Have one unused network like 'unused-vlan-999', assign the template Network Configuration to this VLAN and network connected. So your coding will be easy to change from VLAN 999 to customer desired network.

4. Make sure VMware tools installed in VM before converting to template.

*VDC - Virtual Datacenter.