View lists of the most popular professions in the employment center. You might need to undergo re-qualification courses, then you will get a desired job and a decent pay. If any please note these resources: rspb.ru and edu.jobmarket.ru. For urgent assistance in this matter it is better to contact the unemployment office in Saint-Petersburg.
In St.Petersburg many ways of alternative earnings. Given the specificity of the city, you can find a job as a model at an art Academy or University, an apprenticeship in the creative Studio. Saint Petersburg is a tourist center, so there are many vacancies in this area: greeters and group assistant, courier, assistant guide, driver.
Perhaps you have a small apartment, which is not very beneficial to take in the long term. You can place ads at travel agencies or on the forums that you have comfortable apartments and rent them by the day.
In St.-Petersburg much is housing construction, so if you are really good at working with your hands, you can get in a construction crew plumber, tiler, electrician or painter. These vacancies are especially in high demand in the market of these services.
If you want to establish a small business and carry small wholesale products from Finland, you can count on high-quality transport there and back and the warehouses of temporary storage.
There is also a lot of seasonal jobs in the sphere of housing and communal services, so you can feel free to contact the housing office of his district, for example, during heavy snowfalls.
Be prepared to improvise and look for work in different professional fields.